tag:theconversation.com,2011:/fr/topics/food-poisoning-7983/articlesFood poisoning – The Conversation2024-02-22T17:26:22Ztag:theconversation.com,2011:article/2236222024-02-22T17:26:22Z2024-02-22T17:26:22ZMan eats raw chicken for 25 days – why isn’t he sick?<figure><img src="https://images.theconversation.com/files/577277/original/file-20240222-26-3nziwl.jpg?ixlib=rb-1.1.0&rect=37%2C47%2C6256%2C4152&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Don't try this at home.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/meat-blender-on-table-494972962">Daria Miroshnikova/Shutterstock</a></span></figcaption></figure><p>John (surname withheld) is an influencer from Florida who has gained notoriety by eating raw chicken for at <a href="https://www.dailymail.co.uk/tvshowbiz/article-13076167/Man-eats-raw-chicken-25-days-straight-bizarre-dietary-experiment-arent-dead.html">least 25 days</a>.</p>
<p>He uses a blender to grind up the uncooked chicken (wing and breast) with flavourings, raw eggs and lettuce before drinking this chicken smoothie. Raw chicken and eggs have a significant infection risk from harmful bacteria such as <a href="https://www.cdc.gov/foodsafety/chicken.html#:%7E:text=If%20you%20eat%20undercooked%20chicken,sick%20from%20eating%20contaminated%20poultry">salmonella and campylobacter</a>, which can cause severe illness. </p>
<p>Symptoms of food poisoning include fever, nausea, vomiting, diarrhoea and blood infections that, even in healthy people, can lead to hospitalisation and death. So why has John not fallen sick with food poisoning from such an unconventional and potentially deadly diet?</p>
<p>John says that he has contacted doctors about the safety aspects of his raw chicken diet, which makes one wonder if prophylactic antibiotics were advised to protect him from infection. Even if not, John, like all humans, has innate protective mechanisms against food poisoning. The stomach has highly acidic fluids with a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7684463/">pH of 1.5 to 2</a>.</p>
<p>Food poisoning germs are sensitive to acid, which damages their DNA, and stomach acid can even kill them. In the stomach, germs also have to overcome other barriers such as digestive enzymes, entrapping mucus and immune system defences.</p>
<p>The stomach empties after <a href="https://journals.lww.com/jcge/abstract/2012/03000/gastric_emptying_scintigraphy__is_four_hours.7.aspx">about four hours</a> so there is a good amount of time for the stomach acid to sanitise John’s blended raw chicken, making chicken germs less able to establish an infection. </p>
<h2>You can’t always rely on innate defences</h2>
<p>However, even in healthy adults, if the number of bacteria is high, stomach acid and immune defences may not be enough to reduce their numbers to a safe level.</p>
<p>Our innate food poisoning defences <a href="https://www.cdc.gov/foodsafety/people-at-risk-food-poisoning.html">may work less effectively</a> in young children, the elderly, pregnant women and those with an underlying health condition or a weakened immune system. </p>
<p>Taking <a href="https://www.nature.com/articles/news010705-3">antacids regularly</a> also increases food poisoning risk by neutralising stomach acid. </p>
<p>John unusually blends his chicken, creating a wide surface area for stomach acid to attack. Also, the source of his chicken and food seasonings might help to protect him from infection.</p>
<p>John says that he gets his chicken from a particular farm, so it’s probably safe to assume the chicken is very fresh and from a flock that might have a lower incidence of salmonella and campylobacter than birds from a larger commercial source. </p>
<p>Freshness is important, as the number of harmful germs increases the older the meat is. If the chicken John is eating is very fresh and he’s not consuming a lot of it, the number of germs may be too low to reach an infectious dose. </p>
<p>However, whatever the pedigree of the chicken, the safety of raw meat is not possible to guarantee, and what looks and smells fresh can still be dangerously germ-laden.</p>
<h2>Seasonings</h2>
<p>John told his followers that he uses seasonings such as soy sauce and herbs to improve the lack of flavour of the raw chicken. It is known that soy sauce promotes digestion by enhancing stomach acid secretion in humans, which would help to kill any germs in the food. Soy sauce also possesses direct <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/antimicrobial-activity">antimicrobial activity</a> against bacteria such as <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/shigella-flexneri"><em>Shigella flexneri</em></a>, <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/staphylococcus-aureus"><em>Staphylococcus aureus</em></a>, <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/vibrio-cholerae"><em>Vibrio cholera</em></a>, <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/salmonella-enterica-serovar-enteritidis"><em>Salmonella enteritidis</em></a> and <a href="https://www.sciencedirect.com/science/article/abs/pii/S138917230570459X?via%3Dihub"><em>Escherichia coli</em></a>.</p>
<p>Chilli sauces also <a href="https://www.cabidigitallibrary.org/doi/pdf/10.5555/20153201654">inhibit food-poisoning bacteria</a>, and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9562244/pdf/main.pdf">many herbs contain antimicrobial compounds</a> and have been used as preservatives for centuries.</p>
<p>Aromatic herbs, such as thyme, are <a href="https://www.sciencedirect.com/science/article/abs/pii/S016816051100078X">potent inhibitors</a> of germ growth, especially the kinds of germ found on poultry.</p>
<h2>How you should eat chicken</h2>
<p>We do not know what John is doing to protect his health while eating the raw chicken, but what is clear is that he is playing a game of food-poisoning roulette. </p>
<p>You cannot remove the bacteria in raw chicken or indeed any raw meat. The only way to make the meat safe to eat is by cooking it. Heat effectively kills harmful germs, and salmonella and campylobacter are neutralised at temperatures above 75°C. </p>
<p>Cooking chicken correctly is the only way you can safely eat chicken and not risk potentially deadly food poisoning.</p><img src="https://counter.theconversation.com/content/223622/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Primrose Freestone does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Florida man eats blended raw chicken but evades food poisoning. A microbiologist explains why.Primrose Freestone, Senior Lecturer in Clinical Microbiology, University of LeicesterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2205072024-02-08T14:09:18Z2024-02-08T14:09:18ZNigeria’s street food: tasty but toxic? Expert shares advice to make it safer<p>In the lively streets of Nigeria’s cities, where delicious street food is a daily delight, a wide variety of food can be bought and consumed instantly. From the sizzling suya snack in Abuja to the aromatic jollof rice in Lagos, street food has become an integral part of Nigerian life. </p>
<p>However, beneath these enticing flavours lies a critical question of public safety and health regulation. There is growing concern about the chemical and microbiological safety of these foods, as there seems not to be any oversight or control in their production and marketing.</p>
<p>Over 70% of urban dwellers in Africa <a href="https://www.ifpri.org/blog/why-brutalizing-food-vendors-hits-africas-growing-cities-where-it-hurts#:%7E:text=Food%20markets%20in%20the%20informal,meat%2C%20fish%2C%20and%20milk.">rely on street vendors</a>. However, inadequate government regulation in developing nations, such as Nigeria, raises concerns about food safety and public health. Foodborne diseases have been <a href="https://www.tandfonline.com/doi/full/10.1080/23311932.2023.2266194">linked</a> with contaminated street foods. Common pathogens include <em>E. coli</em> and <em>Salmonella</em>, which has potential to cause foodborne illnesses such as <a href="https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/gastroenteritis-salmonellosis">gastroenteritis</a>, <a href="https://www.who.int/news-room/fact-sheets/detail/e-coli">haemorrhagic colitis or bloody diarrhoea and life-threatening conditions such as haemolytic uraemic syndrome</a>. Heavy metal contamination is another risk. </p>
<p>This issue is not unique to Nigeria or Africa; it is a <a href="https://link.springer.com/chapter/10.1007/978-981-15-2556-8_7">global challenge</a> in many developing countries where street food is a <a href="https://www.scirp.org/journal/paperinformation?paperid=104389">substantial</a> part of the economy.</p>
<p><a href="https://core.ac.uk/download/pdf/82316865.pdf">Research</a> has explored the role of street-vended foods in meeting socio-economic challenges, particularly in developing nations. Other studies have focused on the microbiological safety of street foods (for example, <a href="https://www.sciencedirect.com/science/article/pii/S0362028X22104229?via%3Dihub">soy wara</a>, a Nigerian curdled soy milk product), and <a href="https://core.ac.uk/download/pdf/82316865.pdf">the risk factors in street food practices</a>. </p>
<p>Our own <a href="https://www.tandfonline.com/doi/full/10.1080/23311932.2023.2266194">study</a> analysed gaps in the safety and regulation of street foods in Nigeria. We highlighted gaps in infrastructure, training and vendor awareness, and made recommendations to solve the problems we identified. </p>
<p>We <a href="https://www.tandfonline.com/doi/full/10.1080/23311932.2023.2266194">found</a> a gap in food safety standards for street-vended foods in Nigeria. While street food vendors <a href="https://www.ajol.info/index.php/ajfand/article/view/163672/153148">provide</a> affordable and accessible meals, the lack of regulation <a href="https://www.tandfonline.com/doi/full/10.1080/23311932.2023.2266194">poses</a> significant health risks. </p>
<h2>Why street food can be unsafe</h2>
<p>The primary concern is hygiene and food handling practices. Inadequate <a href="https://onlinelibrary.wiley.com/doi/full/10.2991/efood.k.200619.001">access to clean water</a>, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8279176/">inappropriate waste disposal</a>, <a href="https://www.sciencedirect.com/science/article/abs/pii/S0956713514004307">temperature abuse</a> and lack of food safety knowledge are common challenges seen among street food vendors. </p>
<p>These conditions can lead to food-borne illnesses, which can be prevented but continue to be a public health issue. The WHO <a href="https://www.who.int/activities/estimating-the-burden-of-foodborne-diseases#:%7E:text=Each%20year%20worldwide%2C%20unsafe%20food,number%20is%20likely%20an%20underestimation.">estimates</a> that each year, there are more than 600 million cases of foodborne illnesses, resulting in over 420,000 deaths, with the greatest burden of these (more than 30%) occuring in children less than 5 years of age. </p>
<p>In Nigeria, there have been pockets of foodborne disease outbreaks over the years which have claimed lives. The Consumer Advocacy for Food Safety and Nutrition Initiative <a href="https://www.gainhealth.org/sites/default/files/publications/documents/report-of-eatsafe-launch-in-nigeria-with-next-steps.pdf#page=3">estimates</a> that 173 million cases of foodborne illnesses occur in Nigeria, resulting in 33,000 deaths annually.</p>
<p>Generally, street food preparation in Nigeria mirrors traditional approaches to food preparation at home. However, <a href="https://jara.org.in/uploads/archivepdf/8025JARA_Vol_03_June_2021_01.pdf">a study in Asaba</a>, Delta State Nigeria highlights that because of the scale and quantity of foods prepared, more than 50% of food processors do not wash raw foods prior to preparation and another 40% of the food processors do not wash their hands. Neither do they practise personal hygiene during the handling of foods. Similarly, many street food vendors <a href="https://pubmed.ncbi.nlm.nih.gov/25258630/">operate in less than perfect environments for food processing</a>: many street food vendor stands have flies, rodents and open waste bins which are risk factors for the contamination of foods. </p>
<p>The lack of a clean and sanitary environment for food processing <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8279176/">has been identified</a> as among the key factors that contribute to the contamination of street foods by microorganisms. </p>
<h2>Checking unsafe practices</h2>
<p>A multifaceted approach to these issues must be adopted. </p>
<ul>
<li><p>Training: First, <a href="https://www.tandfonline.com/doi/full/10.1080/23311932.2023.2266194">basic food safety training for vendors</a> is crucial. This training should cover essential hygiene practices, safe food handling and storage procedures. It can be done through local health departments and community organisations. This recommendation draws on <a href="https://www.food.gov.uk/business-guidance/food-hygiene-for-your-business">established principles</a> of hygiene and safe food handling. Continuous training on food safety has <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0287996">proved</a> effective in promoting food safety.</p></li>
<li><p>Enforcement: The government should <a href="https://www.tandfonline.com/doi/full/10.1080/23311932.2023.2266194">develop and enforce</a> food safety regulations specific to street vendors. This requires a balance between ensuring public health and not stifling the livelihoods of the vendors. Subsidising the cost of necessary equipment like portable sinks or refrigeration units could be a part of this initiative. Supplying vendors with hygienic materials has <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0287996">proved</a> to be valuable for preserving and enhancing food safety in low- and middle-income nations.</p></li>
<li><p>Inspection: Regular inspections should be conducted to ensure compliance with these regulations. These should not be punitive but rather supportive, helping vendors to meet the required standards. A <a href="https://www.food.gov.uk/sites/default/files/media/document/Stage%202%20Process_evaluation%20final%20report.pdf">food hygiene rating scheme</a> should be put in place to identify vendors complying with food safety standards as this could motivate them to improve their sanitary conditions.</p></li>
<li><p>Awareness: Public awareness also plays a vital role. Consumers should be educated about the importance of food safety and how to identify vendors who adhere to hygiene standards. <a href="https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-019-7475-9">Consumer awareness</a> can create a demand for safer practices, encouraging vendors to comply with regulations.</p></li>
<li><p>Research and development: Finally, research and collaboration with food scientists and public health experts can lead to innovative solutions that are tailored to the Nigerian context. For instance, exploring low-cost preservation techniques or developing mobile apps for health inspection ratings could revolutionise the way street food is regulated.</p></li>
</ul>
<h2>Regulations will save lives and livelihoods</h2>
<p>Regulating street food in Nigeria is not just about preventing disease; it is about preserving a way of life in a safe and sustainable manner. At the heart of this issue are the vendors and consumers, whose lives and well-being are interconnected with the very essence of street food culture.</p><img src="https://counter.theconversation.com/content/220507/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Helen Onyeaka does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Street food is popular in Nigeria but safety is not regulated.Helen Onyeaka, Associate Professor, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2174522023-11-20T19:56:02Z2023-11-20T19:56:02ZThis Thanksgiving − and on any holiday − these steps will help prevent foodborne illness<figure><img src="https://images.theconversation.com/files/559841/original/file-20231116-15-tommvh.jpg?ixlib=rb-1.1.0&rect=0%2C21%2C7205%2C5368&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A delicious – and safe – holiday spread involves careful foreplanning and preparation.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/holiday-turkey-dinner-royalty-free-image/836012728?phrase=thanksgiving+dinner&searchscope=image%2Cfilm&adppopup=true">Lauri Patterson/E+ via Getty Images</a></span></figcaption></figure><p>Thanksgiving is a time for gathering with friends and family around the dinner table. No one wants to cause their family or friends to get sick from a foodborne illness on this holiday or any other occasion. </p>
<p>The Centers for Disease Control and Prevention reports that 1 in 6 Americans, or 48 million people, <a href="https://www.cdc.gov/foodborneburden/2011-foodborne-estimates.html">get sick from a foodborne illness</a> each year. According to the CDC, more than 1 million of these people get sick from <a href="https://www.mayoclinic.org/diseases-conditions/salmonella/symptoms-causes/syc-20355329">salmonella</a>, which is the primary pathogen associated with poultry. </p>
<p>As a <a href="https://news.clemson.edu/our-experts/kimberly-baker/">food safety specialist</a>, I educate food producers, manufacturers and consumers on how to ensure the safety of the food they produce.</p>
<p>This Thanksgiving – and, really, for any gathering – make sure you understand how to prepare your meal to ensure that everyone goes home without a foodborne illness. Understanding the safe food practices to follow at home during preparation, cooking, serving and storing leftovers will keep your holiday meal delicious and safe to eat.</p>
<h2>Pathways to foodborne illness</h2>
<p><a href="https://www.cdc.gov/salmonella/general/index.html">Salmonella is a bacteria</a> that causes a foodborne illness called salmonellosis. Salmonella is also often linked to undercooked poultry and beef, undercooked eggs, raw milk and produce. Symptoms of salmonellosis, which include diarrhea, fever and stomach pain, <a href="https://www.foodsafety.gov/food-poisoning/bacteria-and-viruses">can begin six hours to six days</a> after eating contaminated food. </p>
<p>Food contamination occurs when pathogens, toxins or chemicals make their way into food. <a href="https://www.fda.gov/media/83271/download">Common pathogens</a> that are attributed to foodborne illnesses are salmonella, E. coli, listeria and norovirus. Botulism is a foodborne illness that is caused by a toxin that is produced by a bacterium. A bacterial or viral contaminant can get on the food at any point along the <a href="https://www.cdc.gov/foodsafety/production-chain.html">food production chain</a>, from the field, water, equipment, processing, handling, transportation, storage or preparation.</p>
<p>Every person who grows, handles, transports, stores or prepares food along the food production chain plays a very important role in detecting, eliminating or reducing contamination.</p>
<h2>The perennial wisdom of hand-washing</h2>
<p>Any food preparation and handling should always start with hand-washing. </p>
<p>There are five steps to <a href="https://www.foodsafety.gov/blog/wash-your-hands-health">proper hand-washing</a>: </p>
<ul>
<li>Wash hands with running water. </li>
<li>Apply <a href="https://hgic.clemson.edu/snowman-hands-can-prevent-food-borne-illness/">enough soap to create a complete lather</a>.</li>
<li>Scrub hands, including the top, between fingers, around fingernails and wrists for a minimum of 20 seconds.</li>
<li>Rinse hands under running water.</li>
<li>Dry with a paper towel or air dry. </li>
</ul>
<p>Hands should also be washed any time during food preparation that your hands have touched another food or surface that may have pathogens on it. This includes handling raw meat, poultry, seafood or eggs, as well as touching unwashed produce, blowing your nose, touching your cellphone or petting a cat or dog, to name a few.</p>
<p>A study by the U.S. Department of Agriculture’s Food Safety Inspection Service, which is the branch of the USDA that makes sure meat, poultry and eggs are safe for consumption, observed that <a href="https://www.foodsafety.gov/blog/millions-americans-dirty-hands-are-spreading-dangerous-bacteria">97% of study participants failed to wash their hands</a> during food preparation when they should have. So while hand-washing might seem like a no-brainer, clearly it’s not. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/3PmVJQUCm4E?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">It’s hard to overstate the importance of hand-washing prior to food handling.</span></figcaption>
</figure>
<h2>Rinsing the poultry beforehand is a no-no</h2>
<p>While preparing your meal, there are a few critical food-handling steps to follow to prevent cross contamination, or the transfer of pathogens from one surface to another. </p>
<p>First, keep raw meat, poultry and seafood away from raw or ready-to-eat foods. For example, do not prepare your raw turkey next to where you are preparing a salad, or do not cut produce on a cutting board that had raw meat on it without washing it thoroughly first. </p>
<p>Many people may not realize that it is unsafe to rinse poultry before cooking. The USDA recommends <a href="https://www.usda.gov/media/blog/2016/11/16/wash-or-not-wash">leaving poultry unwashed</a> because it can cause pathogens to easily spread throughout the kitchen from the spray of the water. The only exception is a brined turkey. Brined turkeys are required to be rinsed before cooking, but use extra caution when doing so, and be sure to sanitize all surfaces in and around the sink afterward.</p>
<h2>Having a clean work surface is critical</h2>
<p>Another key step to keeping your Thanksgiving meal safe is to effectively <a href="https://extension.colostate.edu/docs/pubs/foodnut/kitchen-sanitize.pdf">clean and sanitize kitchen surfaces and equipment</a> following instructions on your kitchen cleaner. </p>
<p><a href="https://extension.sdstate.edu/make-your-own-kitchen-cleaning-sanitizer">Chlorine bleach</a> is a commonly used sanitizer that can be used in the kitchen, but there are a few things to know before using it. Chlorine bleach works best when mixed with cool – not hot – water and should be made fresh daily before using. To prepare, mix a teaspoon of bleach with one quart of water, and let the solution cover the surface for one minute before wiping, or allow to air dry. </p>
<h2>Cooking the meat to safe temperatures</h2>
<p>Cooking the <a href="https://theconversation.com/why-is-turkey-the-main-dish-on-thanksgiving-193702">Thanksgiving turkey</a> or ham are two more critical steps in preparing a safe holiday meal. </p>
<p>Before cooking turkey, <a href="https://www.usda.gov/media/blog/2016/11/18/how-safely-thaw-turkey">make sure it is completely thawed</a> in the refrigerator. For large birds, this may require up to one week of thawing time, so plan ahead. </p>
<p>All poultry must be cooked to a minimum of 165 degrees Fahrenheit. <a href="https://hgic.clemson.edu/factsheet/how-to-cook-turkey/">Cooking instructions</a> and cooking temperatures will vary based on the cooking method that you choose. But no matter the cooking method, make sure to take the temperature of the turkey in the thickest portion of the breast meat and innermost part of the thigh, being sure not to touch bone with the thermometer. Poultry must be cooked to 165 F because this is the <a href="https://www.fsis.usda.gov/sites/default/files/media_file/2021-12/Appendix-A.pdf">temperature that is required to kill salmonella</a> instantly. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/560489/original/file-20231120-27-f8dj5z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A woman stands in front of a cooked turkey that's sitting on a kitchen counter as she smiles and demonstrates how to handle poultry." src="https://images.theconversation.com/files/560489/original/file-20231120-27-f8dj5z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/560489/original/file-20231120-27-f8dj5z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=350&fit=crop&dpr=1 600w, https://images.theconversation.com/files/560489/original/file-20231120-27-f8dj5z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=350&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/560489/original/file-20231120-27-f8dj5z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=350&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/560489/original/file-20231120-27-f8dj5z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=440&fit=crop&dpr=1 754w, https://images.theconversation.com/files/560489/original/file-20231120-27-f8dj5z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=440&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/560489/original/file-20231120-27-f8dj5z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=440&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Food safety expert Kimberly Baker discusses the finer points of preparing a Thanksgiving turkey.</span>
<span class="attribution"><span class="source">Clemson University</span></span>
</figcaption>
</figure>
<p>Based on the size of your bird and your cooking method, determine the amount of cooking time it will need well ahead of time. If you are cooking it in the oven with other dishes, consider that some extra roasting time may be needed, as the temperature of the oven decreases and extends cooking time every time the oven door is opened. You want to make sure you have enough time to cook the turkey thoroughly and allow approximately 30 minutes of rest time at room temperature before carving.</p>
<p>If you are <a href="https://hgic.clemson.edu/factsheet/holiday-meats-not-just-turkey/">preparing ham</a>, first determine whether it is fully precooked at the time of purchase or if cooking is required. Even if fully cooked, hams still need to be heated to a minimum of 140 F. Those that require cooking need to be cooked to 145 F. Like turkey, roasting time will be based on the size of the ham – plan ahead so you know when to put it in the oven. A thermometer should be used to measure the temperature of the thickest portion of the ham without touching bone.</p>
<h2>Safe handling and storage should not be an afterthought</h2>
<p>Safe handling of the turkey, ham and other side dishes does not end after they are cooked. </p>
<p>If the food is served buffet style and will be kept out at room temperature for an extended period of time, make sure to have a plan to keep hot food hot, which means above 135 F, and cold foods below 40 F, which is equivalent to the maximum safe temperature of a refrigerator. For example, hot foods can be kept hot in a preheated chafing dish, and cold foods can be served in their serving dish that is nestled in a bowl or tray of ice. If you are unable to keep the food hot or cold during service, then make sure they are put away in the refrigerator within two hours after serving. </p>
<p>Thanksgiving leftovers should be stored in the refrigerator for <a href="https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/leftovers-and-food-safety">no more than three to four days</a>. If you have a lot of leftovers that won’t be eaten within this time frame, consider freezing them for a quick meal at a later date, then thaw and eat them within three to four months for best quality. Remember to label and date leftovers so you know what they are and when they were put in the refrigerator or freezer.</p><img src="https://counter.theconversation.com/content/217452/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kimberly Baker does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Keeping guests safe involves far more than just careful cooking − hand-washing, keeping work surfaces clean, safe handling and proper storage are also key ingredients.Kimberly Baker, Food Systems and Safety Program Team Director and Assistant Extension Specialist, Clemson UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2165362023-10-30T04:31:05Z2023-10-30T04:31:05ZWhat is ‘fried rice syndrome’? A microbiologist explains this type of food poisoning – and how to avoid it<figure><img src="https://images.theconversation.com/files/556496/original/file-20231030-21-dnivqx.jpg?ixlib=rb-1.1.0&rect=49%2C0%2C5472%2C3645&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/authentic-chinese-asian-fried-rice-egg-2260046311">Elena Eryomenko/Shutterstock</a></span></figcaption></figure><p>A condition dubbed “<a href="https://www.delish.com/food-news/a45654955/death-from-leftover-pasta-fried-rice-syndrome">fried rice syndrome</a>” has caused some panic online in recent days, after the case of a 20-year-old who died in 2008 was resurfaced on TikTok.</p>
<p>“Fried rice syndrome” refers to food poisoning from a bacterium called <a href="https://www.foodstandards.gov.au/consumer/safety/foodborne-illness/Pages/bacillus-cereus-.aspx"><em>Bacillus cereus</em></a>, which becomes a risk when cooked food is left at room temperature for too long.</p>
<p>The 20-year-old college student died after reportedly eating spaghetti that he cooked, left out of the fridge, and then reheated and ate <a href="https://www.huffpost.com/entry/can-eating-leftover-rice-kill-you-heres-the-science-behind_l_653bb64ce4b05def8bc76b20">five days later</a>. </p>
<p>Although death is rare, <em>B. cereus</em> can cause gastrointestinal illness if food isn’t stored properly. Here’s what to know and how to protect yourself. </p>
<p><div data-react-class="TiktokEmbed" data-react-props="{"url":"https://www.tiktok.com/@drjoe_md/video/7292111107592883502?_r=1\u0026_t=8gvh90sZdcm"}"></div></p>
<h2>What is ‘fried rice syndrome’?</h2>
<p><em>Baccilus cereus</em> is <a href="https://www.foodstandards.gov.au/publications/Documents/Bacillus%20cereus.pdf">a common bacterium</a> found all over the environment. It begins to cause problems if it gets into certain foods that are cooked and not stored properly.</p>
<p>Starchy foods like rice and pasta are often the culprits. But it can also affect <a href="https://edis.ifas.ufl.edu/publication/FS269">other foods</a>, like cooked vegetables and meat dishes. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/gastro-outbreak-how-does-it-spread-and-how-can-we-stop-it-a-gastroenterologist-explains-159329">Gastro outbreak: how does it spread, and how can we stop it? A gastroenterologist explains</a>
</strong>
</em>
</p>
<hr>
<p>Certain bacteria can produce toxins. The longer food that should be refrigerated is stored at room temperature, the more likely it is these toxins will grow. </p>
<p><em>B. cereus</em> is problematic because it has a trick up its sleeve that other bacteria don’t have. It produces a type of cell called a spore, which is very resistant to heating. So while heating leftovers to a high temperature may kill other types of bacteria, it might not have the same effect if the food is contaminated with <em>B. cereus</em>.</p>
<p>These spores are essentially dormant, but if given the right temperature and conditions, they can grow and become active. From here, they begin to produce the toxins that make us unwell.</p>
<h2>What are the symptoms?</h2>
<p>The symptoms of infection with <em>B. cereus</em> include <a href="https://www.foodstandards.gov.au/consumer/safety/foodborne-illness/Pages/bacillus-cereus-.aspx">diarrhoea and vomiting</a>. In fact, there are two types of <em>B. cereus</em> infection: one is normally associated with diarrhoea, and the other with vomiting.</p>
<p>Illness tends to resolve in a few days, but people who are vulnerable, such as children or those with underlying conditions, may be more likely to need medical attention.</p>
<p>Because the symptoms are similar to those of other gastrointestinal illnesses, and because people will often get gastro and not seek medical attention, we don’t have firm numbers for how often <em>B. cereus</em> occurs. But if there’s <a href="https://www.sciencedirect.com/science/article/abs/pii/S0882401023004515">an outbreak</a> of food poisoning (linked to an event, for example) the cause may be investigated and the data recorded.</p>
<figure class="align-center ">
<img alt="An illustration of _Bacillus cereus_." src="https://images.theconversation.com/files/556497/original/file-20231030-21-hzigop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556497/original/file-20231030-21-hzigop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556497/original/file-20231030-21-hzigop.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556497/original/file-20231030-21-hzigop.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556497/original/file-20231030-21-hzigop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556497/original/file-20231030-21-hzigop.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556497/original/file-20231030-21-hzigop.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">‘Fried rice syndrome’ is caused by the bacterium <em>B. cereus</em>.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/bacillus-cereus-grampositive-sporeproducing-bacteria-arranged-480829921">Kateryna Kon/Shutterstock</a></span>
</figcaption>
</figure>
<p>We do know <em>B. cereus</em> is not the most common cause of gastro. Other bugs such as <em>E. coli</em>, <em>Salmonella</em> and <a href="https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/gastroenteritis-campylobacteriosis"><em>Campylobacter</em></a> are probably more common, along with viral causes of gastro, such as norovirus. </p>
<p>That said, it’s still worth doing what you can to protect against <em>B. cereus</em>.</p>
<h2>How can people protect themselves?</h2>
<p>Leftovers should be hot when they need to be hot, and cold when they need to be cold. It’s all about minimising the time they spend in the danger zone (at which toxins can grow). This danger zone is anything above the temperature of your fridge, and below 60°C, which is the temperature to which you should reheat your food.</p>
<p>After cooking a meal, if you’re going to keep some of it to eat over the following days, refrigerate the leftovers promptly. There’s no need to wait for the food to cool.</p>
<p>Also, if you can, break a large batch up into smaller portions. When you put something in the fridge, it takes time for the cold to penetrate the mass of the food, so smaller portions will help with this. This will also minimise the times you’re taking the food out of the fridge. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-when-should-you-throw-away-leftovers-92256">Health Check: when should you throw away leftovers?</a>
</strong>
</em>
</p>
<hr>
<p>As a general guide, you can follow the <a href="https://www.foodstandards.gov.au/foodsafety/standards/Pages/2-hour-4-hour-rule.aspx">two hour/four hour rule</a>. So if something has been out of the fridge for up to two hours, it’s safe to put it back. If it’s been out for longer, consume it then and then throw away the leftovers. If it’s been out for longer than four hours, it starts to become a risk.</p>
<p>The common adage of food safety applies here: if in doubt, throw it out.</p>
<p>It’s also worth keeping in mind the general principles of food hygiene. Before preparing food, wash your hands. Use clean utensils, and don’t cross-contaminate cooked food with raw food.</p><img src="https://counter.theconversation.com/content/216536/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Enzo Palombo does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>‘Fried rice syndrome’ refers to food poisoning from a bacterium called Bacillus Cereus, which becomes a risk when cooked food is left at room temperature for too long.Enzo Palombo, Professor of Microbiology, Swinburne University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2134042023-09-28T15:52:22Z2023-09-28T15:52:22ZI’m a microbiologist and here’s what (and where) I never eat<figure><img src="https://images.theconversation.com/files/550869/original/file-20230928-17-d1ixap.jpg?ixlib=rb-1.1.0&rect=20%2C0%2C6689%2C4476&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/chafing-dish-food-1020163570">Alex Andrei/Shutterstock</a></span></figcaption></figure><p>Every year, around <a href="https://www.ukri.org/news/food-safety-network-to-tackle-9-billion-food-poisoning-challenge/#:%7E:text=Food%20poisoning%20key%20facts%3A,foodborne%20illness%20in%20the%20UK">2.4 million people</a> in the UK get food poisoning – mostly from viral or bacterial contamination. Most people recover <a href="https://www.nhsinform.scot/illnesses-and-conditions/infections-and-poisoning/food-poisoning/">within a few days without treatment</a>, but <a href="https://bmjopengastro.bmj.com/content/7/1/e000377">not all are that lucky</a>.</p>
<p>As a microbiologist, I’m probably more acutely aware of the risk of food-borne infections than most. Here are some of the things I look out for.</p>
<h2>Eating outdoors</h2>
<p>I rarely eat alfresco – whether picnics or barbecues – as the risk of food poisoning goes up when food is taken outdoors. </p>
<p>Keeping your hands clean when handling food is key to not getting sick, but how often do you find hot running water and soap in a park or on a beach? You can use alcohol hand gels (they’re better than nothing), but they don’t kill all germs. </p>
<p>Also, food tends to attract an array of flying and crawling critters, such as flies, wasps and ants, all of which can transfer germs, including <em>E coli</em>, <em>Salmonella</em> and <em>Listeria</em>, to your food. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-fruit-fly-has-landed-in-your-wine-is-it-ok-to-drink-211847">A fruit fly has landed in your wine – is it OK to drink?</a>
</strong>
</em>
</p>
<hr>
<p>Keeping perishable food cold and covered is essential as germs can double in numbers if food is allowed to warm up to 30°C for more than a few hours. For barbecues, meat needs to be thoroughly cooked, and a meat thermometer is a good investment to avoid food poisoning. Do not eat meat if its internal temperature is <a href="https://www.betterhealth.vic.gov.au/health/healthyliving/food-safety-outdoors">less than 70°C</a>. </p>
<h2>Buffets</h2>
<p>Knowing what food-related conditions bacteria prefer to grow in, I am very mindful of the microbiological safety of hot and cold buffet displays. </p>
<p>Indoors, food can be exposed to contamination from insects, dust and above all, people. Food poisoning is, therefore, an inevitable risk when dining at a <a href="https://www.fda.gov/food/buy-store-serve-safe-food/serving-safe-buffets">buffet</a>. </p>
<p>Contamination comes from buffet visitors touching food, and germs can be sprayed on to buffets from people sneezing or coughing close to the food. Even indoors, one must consider contamination by insects, such as flies or wasps, settling on the uncovered food. Also, germs may be deposited from the air, which is rich in bacteria, fungi and viruses. </p>
<p>I always look at the clock when I’m at a buffet as there is a <a href="https://www.cdc.gov/foodsafety/serving-food-safely.html">two-hour catering rule</a>: perishable food will become unsafe to eat within two hours if not kept covered and refrigerated. The problem is buffets tend to be laid out before you arrive, so it is difficult to tell if the platters of cooked meat, seafood, salads, desserts and appetisingly arranged fruit and vegetables will have been sitting for more than two hours when you come to eat them. </p>
<p>For hot buffets, such as those served at breakfast in hotels, I always avoid lukewarm food, as bacteria that cause food poisoning can grow quickly when food is <a href="https://www.fda.gov/food/buy-store-serve-safe-food/serving-safe-buffets">kept at less than 60°C</a>. Hot food should be served hot, that is at a temperature of at least 60°C. If there is any uncertainty about the safety of the food on offer, I reluctantly breakfast on freshly toasted bread and individually packaged marmalade. </p>
<h2>Oysters</h2>
<p>There are some foods I never eat, and raw shellfish, such as oysters, is one of them. This is because oysters are filter feeders and can concentrate germs, such as <em>Vibrio</em> and norovirus, in their tissue. </p>
<p>A <em>Vibrio</em>-contaminated oyster does not look, smell, or taste different, but can still make you very ill. The US Centers for Disease Control and Prevention estimates that about 80,000 people get <em>Vibrio</em> infections from raw oysters, and in the US alone 100 people <a href="https://www.cdc.gov/foodsafety/communication/oysters-and-vibriosis.html">die from vibriosis</a> each year.</p>
<p>It is also possible to pick up food poisoning from eating any raw shellfish (clams, mussels, whelks, cockles). I only eat shellfish that are well-cooked because heat effectively kills harmful germs. </p>
<h2>Bagged salads</h2>
<p>I never eat bagged salads, largely because one of my research areas is fresh salad safety. It has been found that bagged lettuce can contain food poisoning germs such as <em>E coli</em>, <em>Salmonella</em> and <em>Listeria</em>. </p>
<p>My research group <a href="https://journals.asm.org/doi/10.1128/aem.02416-16">has found</a> that these pathogens grow more than a thousand times better when given juices from salad leaves, even if the salad bag is refrigerated. Worryingly, the same germs use the salad juices to become more virulent, and so better at causing an infection.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-sniff-test-is-not-reliable-for-food-safety-heres-why-211808">The sniff test is not reliable for food safety – here's why</a>
</strong>
</em>
</p>
<hr>
<p>For those salad lovers alarmed by this information, most bagged salads are safe if stored refrigerated, washed well before use (even ready-to-eat salad should be washed) and eaten as soon as possible after buying it. </p>
<figure class="align-center ">
<img alt="An open bag of lettuce." src="https://images.theconversation.com/files/550872/original/file-20230928-15-irzk45.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/550872/original/file-20230928-15-irzk45.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/550872/original/file-20230928-15-irzk45.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/550872/original/file-20230928-15-irzk45.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/550872/original/file-20230928-15-irzk45.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/550872/original/file-20230928-15-irzk45.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/550872/original/file-20230928-15-irzk45.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">If there are salad ‘juices’, throw it out.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/open-bag-salad-lettuce-carrots-white-528025258">Noel V. Baebler/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Cooking practices</h2>
<p>In terms of cooking practices, I have a list of dos and don’ts. </p>
<p>For perishable foods, I regularly check use-by dates, but if it is before the expiry date and the food package looks swollen, or when opened the food looks or smells different than expected, I throw it in the bin as it could be contaminated.</p>
<p>I never use the same chopping boards for raw and cooked foods, and washing my hands before and after handling food is instinctual. </p>
<p>One of my “never do” practices is reheating cooked rice. This is because uncooked rice can contain spores of <em>Bacillus cereus</em>, a food-poisoning germ. </p>
<p>Although the <em>Bacillus</em> cells are killed by cooking, the spores survive. If the rice is left to cool and sit at room temperature, <a href="https://www.nhs.uk/common-health-questions/food-and-diet/can-reheating-rice-cause-food-poisoning/#:%7E:text=Yes%2C%20you%20can%20get%20food,been%20stored%20before%20it%E2%80%99s%20reheated">the spores grow into bacteria</a>, which will increase in numbers quickly as rice is a good <em>Bacillus</em> culture medium when at room temperature. </p>
<p>The rice-cultured <em>Bacillus</em> can produce toxins that, within a few hours of ingestion, can cause vomiting and diarrhoea lasting up to 24 hours.</p>
<h2>Dining out</h2>
<p>I find that having a high level of food safety awareness causes me to be first in line for buffets, to be cautious about eating from breakfast bars, and to watch the clock for how often perishable food is replaced. I never collect “doggy bags” of food leftovers (they have usually exceeded the two-hour time limit), even if they really are intended for a pet. </p>
<p>The benefits of being a microbiologist are that we know how to avoid food poisoning and, in return, people have confidence our cooking is very safe to eat.</p><img src="https://counter.theconversation.com/content/213404/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Primrose Freestone has previously received funding from the BBSRC for her salad research work..</span></em></p>You’ll never look at bagged lettuce the same way again.Primrose Freestone, Senior Lecturer in Clinical Microbiology, University of LeicesterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2136212023-09-25T12:21:07Z2023-09-25T12:21:07ZFlesh-eating bacteria infections are on the rise in the US − a microbiologist explains how to protect yourself<figure><img src="https://images.theconversation.com/files/549431/original/file-20230920-17-vywy11.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1576%2C1080&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">_Vibrio vulnificus_ infections are spreading across the U.S. because of climate change.</span> <span class="attribution"><a class="source" href="https://phil.cdc.gov/Details.aspx?pid=7812">CDC/Janice Haney Carr</a></span></figcaption></figure><p>Flesh-eating bacteria sounds like the premise of a bad horror movie, but it’s a growing – and potentially fatal – threat to people.</p>
<p>In September 2023, the Centers for Disease Control and Prevention <a href="https://emergency.cdc.gov/han/2023/han00497.asp">issued a health advisory</a> alerting doctors and public health officials of an increase in flesh-eating bacteria cases that can cause serious wound infections. </p>
<p><a href="https://medicine.iu.edu/faculty/13502/sullivan-william">I’m a professor</a> at the Indiana University School of Medicine, where <a href="https://www.sullivanlab.com/">my laboratory</a> studies <a href="https://scholar.google.com/citations?user=mN6ZaFkAAAAJ&hl=en">microbiology and infectious disease</a>. Here’s why the CDC is so concerned about this deadly infection – and ways to avoid contracting it.</p>
<h2>What does ‘flesh-eating’ mean?</h2>
<p>There are several types of bacteria that can infect open wounds and cause a rare condition called <a href="https://doi.org/10.1097%2F01.NURSE.0000694752.85118.62">necrotizing fasciitis</a>. These bacteria do not merely damage the surface of the skin – they release toxins that destroy the underlying tissue, including muscles, nerves and blood vessels. Once the bacteria reach the bloodstream, they gain ready access to additional tissues and organ systems. If left untreated, necrotizing fasciitis can be fatal, sometimes within 48 hours.</p>
<p>The bacterial species <a href="https://www.cdc.gov/groupastrep/index.html">group A <em>Streptococcus</em></a>, or group A strep, is the most common culprit behind necrotizing fasciitis. But the CDC’s latest warning points to an additional suspect, a type of bacteria called <a href="https://www.cdc.gov/vibrio/wounds.html"><em>Vibrio vulnificus</em></a>. There are only <a href="https://emergency.cdc.gov/han/2023/han00497.asp">150 to 200 cases</a> of <em>Vibrio vulnificus</em> in the U.S. each year, but the mortality rate is high, with 1 in 5 people succumbing to the infection.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/FZrb8ttsfg8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Climate change may be driving the rise in flesh-eating bacteria infections in the U.S.</span></figcaption>
</figure>
<h2>How do you catch flesh-eating bacteria?</h2>
<p><em>Vibrio vulnificus</em> primarily lives in warm seawater but can also be found in brackish water – areas where the ocean mixes with freshwater. Most infections in the U.S. occur in the <a href="https://doi.org/10.1001/jama.2023.0174">warmer months, between May and October</a>. People who swim, fish or wade in these bodies of water can contract the bacteria through an open wound or sore.</p>
<p><em>Vibrio vulnificus</em> can also get into seafood harvested from these waters, especially shellfish like oysters. Eating such foods raw or undercooked can lead to <a href="https://www.cdc.gov/vibrio/food.html">food poisoning</a>, and handling them while having an open wound can provide an entry point for the bacteria to cause necrotizing fasciitis. In the U.S., <em>Vibrio vulnificus</em> is a leading cause of <a href="https://doi.org/10.3389/fmicb.2017.00997">seafood-associated fatality</a>.</p>
<h2>Why are flesh-eating bacteria infections rising?</h2>
<p><em>Vibrio vulnificus</em> is found in warm coastal waters around the world. In the U.S., this includes southern Gulf Coast states. But rising ocean temperatures due to global warming are creating new habitats for this type of bacteria, which can now be found along the East Coast as far north as <a href="https://emergency.cdc.gov/han/2023/han00497.asp">New York and Connecticut</a>. A <a href="https://doi.org/10.1038/s41598-023-28247-2">recent study</a> noted that <em>Vibrio vulnificus</em> wound infections increased eightfold between 1988 and 2018 in the eastern U.S. </p>
<p><a href="https://www.pbs.org/newshour/health/flesh-eating-bacteria-on-the-rise-in-florida-following-hurricane-ian">Climate change</a> is also fueling stronger hurricanes and storm surges, which have been associated with spikes in flesh-eating bacteria infection cases.</p>
<p>Aside from increasing water temperatures, the number of people who are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2762295/">most vulnerable to severe infection</a>, including those <a href="https://theconversation.com/global-diabetes-cases-on-pace-to-soar-to-1-3-billion-people-in-the-next-3-decades-new-study-finds-208832">with diabetes</a> and those taking medications that suppress immunity, is on the rise.</p>
<h2>What are symptoms of necrotizing fasciitis? How is it treated?</h2>
<p><a href="https://www.cdc.gov/groupastrep/diseases-public/necrotizing-fasciitis.html#symptoms">Early symptoms</a> of an infected wound include fever, redness, intense pain or swelling at the site of injury. If you have these symptoms, seek medical attention without delay. Necrotizing fasciitis can <a href="https://www.cdc.gov/groupastrep/diseases-public/necrotizing-fasciitis.html#symptoms">progress quickly</a>, producing ulcers, blisters, skin discoloration and pus.</p>
<p><a href="https://www.cdc.gov/groupastrep/diseases-public/necrotizing-fasciitis.html">Treating flesh-eating bacteria</a> is a race against time. Clinicians administer antibiotics directly into the bloodstream to kill the bacteria. In many cases, damaged tissue needs to be surgically removed to stop the rapid spread of the infection. This sometimes <a href="https://pubmed.ncbi.nlm.nih.gov/33623768/">results in amputation</a> of affected limbs.</p>
<p>Researchers are concerned that an increasing number of cases are becoming impossible to treat because <em>Vibrio vulnificus</em> has evolved <a href="https://doi.org/10.3389/fmicb.2017.00997">resistance to certain antibiotics</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/pGxIXTvSpTM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Necrotizing fasciitis is rare but deadly.</span></figcaption>
</figure>
<h2>How do I protect myself?</h2>
<p>The CDC offers several recommendations to help <a href="https://www.cdc.gov/vibrio/wounds.html">prevent infection</a>. </p>
<p>People who have a fresh cut, including a new piercing or tattoo, are advised to stay out of water that could be home to <em>Vibrio vulnificus</em>. Otherwise, the wound should be completely covered with a waterproof bandage. </p>
<p>People with an open wound should also avoid handling raw seafood or fish. Wounds that occur while fishing, preparing seafood or swimming should be washed immediately and thoroughly with soap and water.</p>
<p>Anyone can contract necrotizing fasciitis, but people with weakened immune systems are <a href="https://doi.org/10.1001/jama.2023.0174">most susceptible to severe disease</a>. This includes people taking immunosuppressive medications or those who have pre-existing conditions such as liver disease, cancer, HIV or diabetes.</p>
<p>It is important to bear in mind that necrotizing fasciitis presently <a href="https://doi.org/10.1097%2F01.NURSE.0000694752.85118.62">remains very rare</a>. But given its severity, it is beneficial to stay informed.</p><img src="https://counter.theconversation.com/content/213621/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bill Sullivan receives funding from the National Institutes of Health.</span></em></p>Warmer ocean waters are fueling the spread of the bacteria Vibrio vulnificus. Infections can lead to a rare but fatal condition called necrotizing fasciitis.Bill Sullivan, Professor of Pharmacology & Toxicology, Indiana UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2061242023-06-04T07:46:48Z2023-06-04T07:46:48ZYour snacks may be delicious, but are they safe?<figure><img src="https://images.theconversation.com/files/528790/original/file-20230529-15-wmgf5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Roasted meat on sticks popularly known as 'Suya' is a common delicacy in Nigeria. </span> <span class="attribution"><span class="source">Pius Utomi Ekpei/AFP via Getty Images</span></span></figcaption></figure><p>Food safety is a concern for Nigerians after <a href="https://guardian.ng/features/600m-people-suffer-from-foodborne-sicknesses-yearly/">increasing reports of food-borne illnesses</a> in recent years. According to the Consumer Advocacy for Food Safety and Nutrition Initiative (CAFSANI), consumption of unsafe food in Nigeria results in about <a href="https://pdf.usaid.gov/pdf_docs/PA00XX8H.pdf#page=3">173 million cases of diarrhoea</a> and approximately 33,000 deaths due to foodborne illnesses. </p>
<p>The country has over the years experienced repeated outbreaks of diseases that can be transmitted through contaminated food, including <a href="https://ncdc.gov.ng/diseases/info/C">cholera</a> and <a href="https://ncdc.gov.ng/diseases/info/L">lassa fever</a>. </p>
<p>Food safety is a global issue affecting everyone, regardless of location or social status. According to the <a href="https://www.who.int/news-room/fact-sheets/detail/food-safety">World Health Organization</a>, food-borne diseases affect an estimated 600 million people annually, resulting in 420,000 deaths globally.<br>
Nigeria has significant challenges <a href="https://www.mdpi.com/2304-8158/10/8/1878#B17-foods-10-01878">when it comes to food safety</a> – behaviour around food hygiene. For most developing countries, it can be difficult to practise food safety when clean water and sanitation aren’t available. Some of the other factors that influence food safety in Nigeria are population growth, income inequality, long food supply chains, education gaps and poor regulation.<br>
As a <a href="https://sciprofiles.com/profile/951517">microbiological expert</a>, I am often asked, “how safe is my snack?” The answer to this is not straightforward. It depends on various factors like where the ingredients come from, and how snacks are prepared and stored. </p>
<p>In Nigeria, snacks are small food items that are eaten between meals – a quick bite, as a stand-alone treat or with a beverage. They may be savoury or sweet. Examples include chin-chin, meat pie, <a href="https://theconversation.com/you-love-amagwinya-puff-puff-bofrot-heres-a-healthier-version-of-africas-favourite-snack-170845">puff-puff</a> (deep fried dough), sausage rolls (gala), suya (grilled meat), akara (bean cake), kilishi (dried beef jerky), roasted corn, plantain and groundnuts. </p>
<p>These are usually available from street vendors, in local markets and from supermarkets. Supermarket snacks usually come pre-packaged from the factories while snacks purchased from street vendors and open markets are packaged in a variety of materials such as newspapers for suya and kilishi, polyethylene bags for chin-chin and puff-puff and reused plastic bottles for groundnuts. This unconventional packaging may increase the risk of <a href="https://doi.org/10.18034/ra.v5i3.315">contamination with microorganisms</a>.</p>
<p>There are simple and effective ways to make snacks safer for everyone. Choosing ingredients from trusted sources and following proper food preparation and storage methods can make a big difference. </p>
<figure class="align-center ">
<img alt="men standing behind piles of fruits and vegetables arranged on tables" src="https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&rect=14%2C22%2C4905%2C3201&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Raw fruits and vegetables can be contaminated at the point of sale. Photo by:Pius Utomi Ekpei/AFP.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/roadside-vendors-display-fruits-for-sale-in-lagos-nigerias-news-photo/1239230464?adppopup=true">from www,gettyimages.com</a></span>
</figcaption>
</figure>
<p>By following the tips I offer here, you can enjoy your snacks and reduce the risk of foodborne diseases. Remember, “an ounce of prevention is worth a pound of cure”.</p>
<h2>Managing the risks</h2>
<p><strong>The source of ingredients:</strong> One of the main things that affect the safety of your snack is where its ingredients come from. Raw materials, including fruits, vegetables and animal products, can be <a href="https://www.sciencedirect.com/science/article/pii/S0740002017310158?via%3Dihub">contaminated with harmful microorganisms</a>, such as bacteria, viruses, and parasites. </p>
<p>These microorganisms can cause food-borne illnesses if they are not properly handled and cooked.</p>
<p>To reduce the risk of contamination, it is important to buy <a href="https://www.betterhealth.vic.gov.au/health/healthyliving/food-safety-when-shopping">ingredients from trusted suppliers</a> who have good hygiene practices. </p>
<p>When buying fresh produce, look for signs of spoilage, such as mould, discolouration and foul odours. Avoid buying pre-cut fruits and vegetables, as they are more susceptible to contamination. Always wash fruits and vegetables thoroughly with clean running water before using them.</p>
<p>There are also things to watch out for when buying processed food. Food processing, such as canning and freezing, can kill harmful microorganisms and <a href="https://www.betterhealth.vic.gov.au/health/healthyliving/food-processing-and-nutrition">extend the shelf life of products</a>. But poor processing and handling can lead to contamination and spoilage. </p>
<p><strong>Safe handling and storage:</strong> It’s important to follow <a href="https://www.cdc.gov/handwashing/handwashing-kitchen.html">good hygiene practices</a>, such as washing your hands thoroughly with soap and water before handling food and using clean utensils and equipment. To avoid <a href="https://www.food.gov.uk/safety-hygiene/avoiding-cross-contamination">cross-contamination</a>, separate raw and cooked foods and use different cutting boards for different types of food. Cook food to the <a href="https://www.healthline.com/health/what-temperature-kills-bacteria">appropriate temperature</a> to kill any harmful microorganisms present.</p>
<p>Proper storage can prevent the growth of harmful microorganisms and extend the shelf life of products. <a href="https://opentextbc.ca/foodsafety/chapter/storage-temperatures-and-procedures/">Store perishable items</a>, such as meats, dairy products and cooked foods, in the refrigerator at temperatures of 40°F (4°C) or below. </p>
<p><a href="https://countrylifefoods.com/blogs/country-life-feed/a-quick-guide-on-how-to-store-dried-beans-nuts-and-other-pantry-items">Keep dry foods</a>, such as crackers, cookies and chips, in a cool, dry place away from moisture and heat.</p>
<p><strong>Packaging and labelling:</strong> The <a href="https://www.nafdac.gov.ng/wp-content/uploads/Files/Resources/Guidelines/FOOD/Guidelines%20For%20Food%20Labelling_Labelling.pdf">packaging and labelling</a> of snacks provide important and valuable information about their safety. Look out for products with clear, easy-to-read labels that include information about the <a href="https://www.inecta.com/blog/food-labeling-requirements-what-you-should-know">ingredients, nutritional content and allergens</a>. </p>
<p>Products with damaged or bulging packaging should be avoided as this could be a sign of contamination or spoilage.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/nigerias-street-food-adds-to-the-plastic-problem-green-leaves-offer-a-solution-203618">Nigeria’s street food adds to the plastic problem – green leaves offer a solution</a>
</strong>
</em>
</p>
<hr>
<h2>Symptoms of food-borne diseases</h2>
<p>Knowing the <a href="http://www.aimspress.com/article/10.3934/microbiol.2017.3.529">most common types of foodborne illnesses</a> and their symptoms is very important. The most common microorganisms that cause food-borne illnesses include salmonella, E. coli, listeria and norovirus. </p>
<p>Symptoms of food-borne illness can range from mild, such as nausea and diarrhoea, to severe, such as kidney failure and paralysis – the inability to move some or all parts of your body.</p>
<p>If you experience or observe any symptoms of food-borne illness after eating a snack, seek medical attention immediately. Food-borne infections can spread quickly, and it is important to take preventive measures to avoid the spread. <a href="https://www.cdc.gov/handwashing/when-how-handwashing.html">Wash your hands</a> frequently and avoid food preparation or handling until you fully recover.</p>
<p>In conclusion, ensuring the safety of your snack requires careful consideration of various factors that can affect its quality and safety. These include the source of ingredients, processing and preparation methods, storage, packaging, labelling, and awareness of common food-borne illnesses.</p><img src="https://counter.theconversation.com/content/206124/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Helen Onyeaka does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Food safety means checking the source and paying attention to hygiene and storage.Helen Onyeaka, Associate Professor, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2050872023-05-16T14:41:27Z2023-05-16T14:41:27ZHow does food get contaminated? The unsafe habits that kill more than 400,000 people a year<figure><img src="https://images.theconversation.com/files/526039/original/file-20230514-182951-p8iehb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Food-borne illnesses usually present as diarrhoea, vomiting and stomach pains. </span> <span class="attribution"><span class="source">Getty Images</span></span></figcaption></figure><p><em>Unsafe foods, according to the <a href="https://www.who.int/news/item/07-03-2022-world-food-safety-day-2022-theme-highlights-the-role-that-safe-nutritional-food-plays-in-ensuring-human-health">World Health Organization</a> (WHO), contribute to poor health, including impaired growth and development, micro-nutrient deficiencies, noncommunicable and infectious diseases, and mental illness. Globally, one in ten people are affected by food-borne diseases each year. Antonina Mutoro, a nutrition researcher at the African Population and Health Research Center, explains what causes food contamination and how we can lower the risk of disease.</em></p>
<hr>
<iframe id="noa-web-audio-player" style="border: none" src="https://embed-player.newsoveraudio.com/v4?key=x84olp&id=https://theconversation.com/how-does-food-get-contaminated-the-unsafe-habits-that-kill-more-than-400-000-people-a-year-205087&bgColor=F5F5F5&color=D8352A&playColor=D8352A" width="100%" height="110px"></iframe>
<h2>What is food contamination?</h2>
<p>Access to safe and nutritious food is a basic human right which many do not enjoy, partly because of food contamination. This is defined as the presence of harmful chemicals and microorganisms in food that can cause illness. According to the WHO, food contamination affects about <a href="https://www.who.int/news-room/fact-sheets/detail/food-safety">one in every ten people</a> globally and causes about <a href="https://www.who.int/news-room/fact-sheets/detail/food-safety">420,000 deaths annually</a>. </p>
<p>Food contamination can be:</p>
<ul>
<li><p><strong>physical:</strong> foreign objects in food can potentially cause injury or carry disease-causing microorganisms. Pieces of metal, glass and stones can be choking hazards, or cause cuts or damage to teeth. Hair is another physical contaminant.</p></li>
<li><p><strong>biological:</strong> living organisms in food, including microorganisms (bacteria, viruses and protozoa), pests (weevils, cockroaches and rats) or parasites (worms), can cause disease. </p></li>
<li><p><strong>chemical:</strong> substances like soap residue, pesticide residue and toxins produced by microorganisms such as <a href="https://theconversation.com/what-must-be-done-to-get-toxin-out-of-kenyas-food-supply-127137">aflatoxins</a> can lead to poisoning.</p></li>
</ul>
<h2>What are the most common causes of food contamination?</h2>
<p>The most common cause of food contamination is poor food handling. This includes not washing your hands at the appropriate time – before eating and preparing food, after using the toilet, or after blowing your nose, coughing or sneezing. Using dirty utensils, not washing fruits and vegetables with clean water, and storing raw and cooked food in the same place can also be harmful. Sick people should not handle food. And you should avoid consuming under-cooked foods, particularly meat.</p>
<p>Poor <a href="https://theconversation.com/vegetable-farmers-in-urban-ghana-dont-worry-much-about-food-safety-but-they-should-143706">farming practices</a> can also contaminate food. This includes the heavy use of pesticides and <a href="https://theconversation.com/chickens-from-live-poultry-markets-in-nigeria-could-be-bad-for-your-health-scientists-explain-why-192646">antibiotics</a>, or growing fruits and vegetables using contaminated soil and water. The use of inadequately composted or raw animal manure or sewage is also harmful. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/power-cuts-and-food-safety-how-to-avoid-illness-during-loadshedding-200586">Power cuts and food safety: how to avoid illness during loadshedding </a>
</strong>
</em>
</p>
<hr>
<p>Fresh foods can lead to a number of illnesses. In Kenya, for instance, the <a href="https://bmcresnotes.biomedcentral.com/articles/10.1186/1756-0500-7-627">contamination of meat</a>, <a href="https://www.researchgate.net/publication/329170819_Consumer_Risk_Exposure_to_Chemical_and_Microbial_Hazards_Through_Consumption_of_Fruits_and_Vegetables_in_Kenya">fruits</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/24968591/">vegetables</a> with human waste is relatively common. This is attributed to the use of contaminated water to wash food. Flies carrying contaminants can also directly transfer faecal matter and bacteria onto plant leaves or fruits.</p>
<p><a href="https://theconversation.com/informal-food-markets-what-it-takes-to-make-them-safer-161601">Street foods</a> are another common source of food contamination. These foods are widely consumed in low- and middle-income countries because they’re cheap and easily accessible. </p>
<h2>What are the signs that you’ve eaten contaminated food?</h2>
<p>Biological and chemical substances are the most common food contaminants. They account for <a href="https://www.who.int/news-room/fact-sheets/detail/food-safety">more than 200 food-borne illnesses</a>, including <a href="https://theconversation.com/explainer-causes-symptoms-and-cures-of-typhoid-fever-53645">typhoid</a>, <a href="https://theconversation.com/explainer-why-cholera-remains-a-public-health-threat-74444">cholera</a> and <a href="https://theconversation.com/what-led-to-worlds-worst-listeriosis-outbreak-in-south-africa-92947">listeriosis</a>. Food-borne illnesses usually present as diarrhoea, vomiting and stomach pains.</p>
<p>In severe cases, food-borne illnesses can lead to neurological disorders, organ failure and even death. It’s therefore advisable to seek immediate medical attention if you begin to experience symptoms like persistent diarrhoea and vomiting after eating or drinking.</p>
<p>Children aged under five are the most vulnerable to food-borne illnesses. They bear <a href="https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1001923">40%</a> of the food-borne disease burden. A child’s immune system is still developing and can’t fight off infections as effectively as an adult’s. </p>
<p>In low- and middle-income countries, reduced immunity in children can also occur as a result of malnutrition and frequent exposure to infections due to poor hygiene and sanitation, including a lack of access to safe water and toilets. Additionally, when children are ill, they tend to have poor appetites. This translates to reduced food intake. Coupled with increased nutrient losses through diarrhoea and vomiting, this can lead to a cycle of infection and malnutrition and, in extreme cases, death. </p>
<p>Pregnant women and people with <a href="https://theconversation.com/how-do-i-improve-my-immunity-expert-shares-tips-on-what-to-do-and-what-to-avoid-198537">reduced immunity</a> due to illness or age are equally vulnerable and extra care should, therefore, be taken to prevent food-borne illnesses among these groups.</p>
<h2>What can we do to prevent food contamination?</h2>
<p>Food-borne illnesses also have negative economic impacts, especially in low- and middle-income countries. The World Bank estimates it costs more than <a href="https://www.worldbank.org/en/news/press-release/2018/10/23/food-borne-illnesses-cost-us-110-billion-per-year-in-low-and-middle-income-countries#:%7E:text=The%20total%20productivity%20loss%20associated,estimated%20at%20US%24%2015%20billion.">US$15 billion</a> annually to treat these illnesses in these countries. So it’s important to have preventive strategies in place.</p>
<p>Food contamination can be prevented through simple measures:</p>
<ul>
<li><p>washing your hands at key times (before preparing, serving or eating meals; before feeding children, after using the toilet or after disposing of faeces) </p></li>
<li><p>wearing clean, protective clothing during food preparation </p></li>
<li><p>storing food properly</p></li>
<li><p>washing raw foods with clean water</p></li>
<li><p>keeping raw and cooked foods separate</p></li>
<li><p>using separate utensils for meats and for food meant to be eaten raw. </p></li>
</ul>
<p>Good farming practices, such as the use of clean water and application of approved pesticides in recommended amounts, can help prevent food contamination. </p>
<p>Food vendors also need to be trained on food safety, and provided with clean water and proper sanitation. </p>
<p>As part of the research team at the African Population and Health Research Center, I’m working on the <a href="https://healthyfoodafrica.eu/blog/promoting-access-to-nutritious-food-in-nairobi-urban-poor-settings/">Healthy Food Africa project</a>, which aims to boost food security in urban informal settlements through the promotion of food safety. In Kenya, the project is working closely with the Nairobi county government to develop a food safety training manual targeting street food vendors. This will go a long way towards improving food safety in the city.</p><img src="https://counter.theconversation.com/content/205087/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Antonina Mutoro does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Biological and chemical substances are the most common food contaminants and account for over 200 food-borne illnesses.Antonina Mutoro, Postdoctoral Research Scientist, African Population and Health Research CenterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2005862023-05-01T10:41:49Z2023-05-01T10:41:49ZPower cuts and food safety: how to avoid illness during loadshedding <figure><img src="https://images.theconversation.com/files/522112/original/file-20230420-201-bpqhqv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Keep as little food as possible in your fridge and freezer.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p><em>South Africa has been grappling with power cuts for <a href="https://www.myggsa.co.za/when-did-load-shedding-first-start-in-south-africa/">15 years</a>, which have <a href="https://www.resbank.co.za/content/dam/sarb/publications/quarterly-bulletins/boxes/2022/december/Measures%20of%20electricity%20load-shedding.pdf">worsened in recent years</a>. The persistent power outages have disrupted <a href="https://theconversation.com/africa/search?q=power+cuts">every facet of life</a>, including <a href="https://theconversation.com/your-fridge-might-not-be-cold-enough-to-keep-food-safe-70262">food safety</a>. The Conversation Africa’s Ina Skosana spoke to food safety expert Lise Korsten about the impact of persistent power cuts on the food in our homes and the best ways to protect ourselves.</em> </p>
<hr>
<h2>How should we manage the food in our fridges?</h2>
<p>The reality is that loadshedding for extended periods of time is causing temperature fluctuations in our fridges. Particularly if the fridge is regularly opened during loadshedding or if it has old rubber sealants. Temperature fluctuations can make food go bad. </p>
<p>To start with, let’s consider “what’s in our fridges”, “do we really need to keep so much perishable food in our fridges” and “how safe is it, given current loadshedding schedules”.</p>
<p>Loadshedding is forcing us to think about food safety and spoilage, our general behaviour in terms of food purchases, storage, managing our fridges, hygiene and the use of leftover food. </p>
<p>We need to ask ourselves: “are we buying more food than we should, and are we not wasting more food?”</p>
<p>Perhaps we should consider a more minimalist lifestyle if we are to survive the current economic downturn and manage the impact of loadshedding. </p>
<p>Keeping too much food in fridges increases the potential risk of food-borne illness given our current energy crises. In short, households need to better manage the food in fridges and keep as little of it as possible. </p>
<h2>What’s the best way to avoid illness?</h2>
<p>Keep your fridge – and kitchen – clean. Doing so will reduce the potential of organisms that can proliferate in these environments and cause illnesses, such as food poisoning. There are a few basic ways to maintain hygiene:</p>
<ul>
<li><p>regularly clean your fridge and keep a special eye on obvious potential contamination points such as areas where, for instance, the blood from raw meat dripped onto the bottom shelf </p></li>
<li><p>defrost your freezer to remove any ice building up that can affect the performance of the freezer. </p></li>
</ul>
<p>New fridges often maintain the temperature more effectively for longer periods of time due to new, well-fitting seals. If it’s an older fridge and the rubber seals are broken or the door doesn’t close properly, temperature fluctuations will more likely occur.</p>
<p>A good rule is also to keep your fridge closed during loadshedding and pack more higher risk items towards the back where less temperature fluctuations will occur. The door of the fridge is a higher risk area because of higher temperature fluctuations. This is important since we often keep milk in this compartment, thereby increasing the risk of it going off before the use-by date. </p>
<p>So set your fridge or freezer temperature correctly, and make sure it’s clean and fully functional. The key is keep the temperature consistent and manage the stocks in your fridge. </p>
<h2>Why does fridge temperature matter?</h2>
<p>We don’t get sick from just one organism. We get sick from a certain number of tiny organisms. What is important to keep in mind is that some microorganisms can multiply rapidly – in fact some every <a href="https://www.sciencedirect.com/science/article/abs/pii/B9780433101000500091">20 minutes</a>, others even every <a href="https://blogs.udla.edu.ec/haccp/2017/05/25/bacteria-and-how-they-multiply/#:%7E:text=In%20the%20right%20conditions%2C%20a,would%20have%20over%208%2C000%20bacteria.">10 minutes</a>. </p>
<p>Environmental conditions – such as fluctuating temperatures – will influence how many organisms are present at a certain point in time and can multiply. If the food is kept at temperatures that fluctuate it will encourage rapid growth of microorganism to levels high enough to cause illness by the time the food is consumed. </p>
<p>In general, microorganisms can multiply at temperatures between 4°C and 60°C. This temperature range is often called the “danger zone” in food safety. Some of these organisms prefer room temperature to rapidly multiply. Leaving food outside the fridge is, therefore, risky behaviour since you do not know if food is contaminated with any pathogens or if general spoilage can occur. The strategy is, therefore, to prevent contamination or “slow down” the growth of organisms through effective cold chain management. </p>
<p>The amount of microorganisms in food that can cause illnesses varies. It can be as little as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2553879/">10 or 100 colony forming units</a> – the number of microbial cells in a sample that are able to multiply – per gramme of food. Some organisms can make us sick very quickly, even if only a few cells were initially present. Others increase in number over time when temperatures fluctuate, making food temperature management important. </p>
<p>It’s also important to remember that not all microorganisms are enemies. Less <a href="https://microbiologysociety.org/why-microbiology-matters/what-is-microbiology/microbes-and-the-human-body/microbes-and-disease.html">than 1%</a> actually make us sick. We need to understand the microbial balance in nature and manage the system to our benefit. </p>
<h2>Is it safe to eat leftovers?</h2>
<p>It’s interesting to mention <a href="https://journals.sagepub.com/doi/10.1177/0020872817742703">a study</a> where waste pickers were asked how they know when food is safe to eat. They explained reliance on basic skills and instinct, which in essence means sensory parameters: smelling if food is off, touch (that slimy feeling), that “look” (texture and offish) and memory – once you have been sick from a specific food item your body will instinctively react (almost like a shiver down the spine). </p>
<p>These instincts are important and are in a way a survival skill, so be stringent when keeping leftover food. If you do, try and consume it as soon as possible, preferably the next day. Also, if you heat something, do so properly. A golden rule is to avoid reheating food, especially not more than once. Keep in mind that microorganisms can survive high and low temperatures, and can rapidly multiply during the cooling down periods. So your timeline for safety gets less the longer you keep your food and expose it to fluctuating temperatures.</p>
<p>If possible, make sure you only prepare enough food for a meal, and try and keep fewer leftovers in your fridge. We should also start thinking about eating smaller portions and ask ourselves the question: do our bodies really need that volume of food? It is better, for our mind and soul, to be more conscious of using food wisely and wasting less. This is important in a country where a <a href="https://theconversation.com/south-africas-hunger-problem-is-turning-into-a-major-health-crisis-183736">very high percentage</a> of people go to bed hungry every night.</p>
<h2>So what to do?</h2>
<p>We all have time constraints, with the majority of people getting home late at night and having to rapidly prepare a healthy, safe meal. So plan meal portions, preparation and serving times around loadshedding, and manage the food in the fridge more wisely.</p><img src="https://counter.theconversation.com/content/200586/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lise Korsten does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The era of stocking pantries and keeping our fridges and freezers full is over.Lise Korsten, Professor in the Department of Microbiology and Plant Pathology and Co-Director at the Centre of Excellence in Food Security, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1927232023-01-05T20:37:28Z2023-01-05T20:37:28ZNo, you shouldn’t wash raw chicken before cooking it. So why do people still do it?<figure><img src="https://images.theconversation.com/files/490251/original/file-20221018-17274-k1s6c8.jpg?ixlib=rb-1.1.0&rect=0%2C18%2C6256%2C4108&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Food safety authorities and regulators <a href="https://foodsafety.asn.au/topic/tips-poultry/">around</a> <a href="https://www.cdc.gov/foodsafety/chicken.html#:%7E:text=after%20handling%20chicken.-,Do%20not%20wash%20raw%20chicken.,that%20previously%20held%20raw%20chicken.">the</a> <a href="https://www.food.gov.uk/safety-hygiene/cleaning">world</a> <a href="https://www.mpi.govt.nz/food-safety-home/preparing-and-storing-food-safely-at-home/clean-cook-chill/#:%7E:text=Don't%20wash%20raw%20chicken,food%20poisoning%20from%20campylobacter%20bacteria.">recommend</a> you don’t wash raw poultry before cooking. </p>
<p>That’s because washing chicken can splash dangerous bacteria around the kitchen. It’s best just to thoroughly cook the chicken without washing it, so it is safe to eat.</p>
<p>Despite this, chicken-washing remains common. A <a href="https://www.safefood.qld.gov.au/newsroom/does-raw-chicken-need-rinsing/">survey</a> by Australia’s Food Safety Information Council showed almost half of Australian home cooks washed whole chickens before cooking. Dutch research found <a href="https://www.foodsafetynews.com/2022/05/dutch-survey-finds-a-quarter-of-people-wash-chicken-despite-expert-advice/">25%</a> of consumers washed their chicken often or almost always.</p>
<p>So why do people do it – and what does the research say about the risks of chicken-washing?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/490247/original/file-20221017-18129-wt6pzf.jpg?ixlib=rb-1.1.0&rect=0%2C48%2C5391%2C3535&q=45&auto=format&w=1000&fit=clip"><img alt="A person washes chicken over a sink." src="https://images.theconversation.com/files/490247/original/file-20221017-18129-wt6pzf.jpg?ixlib=rb-1.1.0&rect=0%2C48%2C5391%2C3535&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/490247/original/file-20221017-18129-wt6pzf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/490247/original/file-20221017-18129-wt6pzf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/490247/original/file-20221017-18129-wt6pzf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/490247/original/file-20221017-18129-wt6pzf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/490247/original/file-20221017-18129-wt6pzf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/490247/original/file-20221017-18129-wt6pzf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Australia’s Food Safety Information Council recommends raw poultry not be washed before cooking.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/yes-you-can-reheat-food-more-than-once-heres-why-184158">Yes, you can reheat food more than once. Here's why</a>
</strong>
</em>
</p>
<hr>
<h2>Chicken meat and germs</h2>
<p>Incorrect cooking temperatures and cross-contamination between different foods are two of the most important factors linked to foodborne illness. </p>
<p>This is particularly relevant to poultry meat. Two leading causes of foodborne illness are the bacteria <em><a href="https://www.cdc.gov/campylobacter/index.html">Campylobacter</a></em> and <em><a href="https://www.cdc.gov/foodsafety/communication/salmonella-food.html">Salmonella</a></em>, which are commonly found on raw poultry. </p>
<p>In Australia, reported cases of <em>Campylobacter</em> and <em>Salmonella</em> have almost <a href="https://foodsafety.asn.au/topic/tips-poultry/">doubled</a> over the last two decades. </p>
<p>Of the estimated 220,000 cases of <em>Campylobacter</em> infection each year, <a href="https://foodsafety.asn.au/topic/tips-poultry/">50,000</a> can be attributed either directly or indirectly to chicken meat. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/491574/original/file-20221025-19-osvds4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Chicken is grilled on a barbecue." src="https://images.theconversation.com/files/491574/original/file-20221025-19-osvds4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/491574/original/file-20221025-19-osvds4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/491574/original/file-20221025-19-osvds4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/491574/original/file-20221025-19-osvds4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/491574/original/file-20221025-19-osvds4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/491574/original/file-20221025-19-osvds4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/491574/original/file-20221025-19-osvds4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Why do many home cooks continue to wash chicken before cooking?</span>
<span class="attribution"><a class="source" href="https://www.pexels.com/photo/barbecue-bbq-beef-chicken-262945/">Photo by Pixabay</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Chicken-washing myths, busted</h2>
<p>One <a href="https://doi.org/10.1016/j.foodcont.2020.107682">analysis</a> of consumer responses to an education campaign about the dangers of washing raw poultry shed light on why many people still wash raw chicken before cooking.</p>
<p>Some believe there is a need to wash faeces and other matter off the chicken meat. In fact, modern processing techniques mean chicken carcasses do not need additional cleaning. </p>
<p>Others believe washing with a slightly acidic solution (such as vinegar or lemon juice) will kill bacteria. </p>
<p>On the contrary, <a href="https://doi.org/10.1016/j.foodcont.2018.06.034">research</a> has shown washing raw poultry in lemon juice or vinegar does not remove bacteria and can increase the cross-contamination risk.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1519397720200339456"}"></div></p>
<h2>Washing chicken splashes bacteria around</h2>
<p>One of the more compelling arguments why washing raw poultry under a running tap is a risky activity comes from <a href="https://doi.org/10.1063/5.0083979">recent research</a> on water droplets ejected from the surface of washed chicken. </p>
<p>The study clearly showed bacteria can be transferred from the surface of the chicken to surrounding surfaces via water droplets.</p>
<p>Using high-speed imaging, the researchers found a higher tap height can increase splashing. </p>
<p>Chicken meat is often soft and the water flow can create a divot in the surface. This leads to splashing that would not occur on a curved, hard surface. </p>
<p>The researchers placed large agar plates next to the chicken surfaces to capture any water droplets. This allowed them to grow the bacteria that were transferred with the splashed water. </p>
<p>They found the level of bacterial transmission increased with greater tap height and water flow rate. </p>
<p>Aerated water (which is what you get when the tap is running very hard) also increased splashing and bacterial transmission. </p>
<h2>What if I still really want to wash my chicken meat?</h2>
<p>While washing raw poultry is not recommended, it appears some home cooks are reluctant to let go of this old habit. </p>
<p>If you insist on washing chicken meat, consider doing so in a sink of water rather than under a running tap.</p>
<p>Use a paper towel to mop up any liquids, dispose of the towel and clean up afterwards. </p>
<p>This will help reduce the risk of cross-contamination and keep the kitchen safe. And please wash your hands after handling raw meat! </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-when-should-you-throw-away-leftovers-92256">Health Check: when should you throw away leftovers?</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/192723/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Enzo Palombo does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Washing raw chicken can splash bacteria around the kitchen. It’s best just to properly cook the chicken without washing it. So why do people still wash? Time to bust some chicken-washing myths.Enzo Palombo, Professor of Microbiology, Swinburne University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1894172022-09-13T15:25:04Z2022-09-13T15:25:04ZListeria: how the cost of living crisis could increase the risk of food poisoning<p>More than half the people in the UK say that their health has been <a href="https://tinyurl.com/wdw9jyms">negatively affected</a> by the rising cost of living, according to a YouGov poll. Rising energy and food prices can certainly harm people’s health in many ways – but there’s one way that hasn’t been much discussed. As a food-safety expert, my concern is that it might increase rates of a particularly deadly food poisoning called listeriosis.</p>
<p>Listeriosis is food poisoning caused by the bacteria <em>Listeria monocytogenes</em>. Symptoms might begin a few days after a person has eaten contaminated food, but it can take 30 days or more before the first symptoms appear. These can include a high temperature, aches, tiredness, nausea, vomiting and diarrhoea. But for people with weakened immune systems, listeriosis can result in severe life-threatening issues, such as meningitis and sepsis. </p>
<p>Although the number of people who get listeriosis each year is low, the disease is particularly deadly. Even <a href="https://www.fda.gov/animal-veterinary/animal-health-literacy/get-facts-about-listeria">with antibiotic treatment</a>, between <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/listeria">20% and 40% of people with listeriosis die</a>. So even a small increase in cases is still bad news.</p>
<p>Listeria is commonly associated with chilled ready-to-eat foods that don’t need to be cooked or reheated, such as <a href="https://www.bbc.co.uk/news/health-62875544">smoked fish</a>, <a href="https://www.bbc.co.uk/news/world-africa-43279627">ready-to-eat meats</a>, <a href="https://www.bbc.co.uk/news/uk-scotland-38321313">unpasteurised cheeses</a>, and <a href="https://www.foodsafetynews.com/2021/10/study-suggests-missed-chances-on-listeria-prevention-in-sandwiches/">salads and sandwiches</a>. The steps we can take to reduce the risk of listeriosis are ensuring our fridges are running at temperatures below 5°C, sticking to the use-by dates on foods and following the opened storage duration instructions.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/mOXU7Yuhsds?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Food Standards Agency explains Listeria.</span></figcaption>
</figure>
<p>The <a href="https://www.food.gov.uk/safety-hygiene/chilling">Food Standards Agency</a> recommends that home fridges be set at 5°C or below. However, Elizabeth Redmond, a professor of food safety at Cardiff Metropolitan University, and I have found that <a href="https://meridian.allenpress.com/jfp/article/79/12/2119/174760/Time-Temperature-Profiling-of-United-Kingdom">most fridges operate at 8°C</a>. </p>
<p>Although this slows the growth of some bacteria, this is not the case with listeria. In a <a href="https://www.foodprotection.org/publications/food-protection-trends/archive/2019-05-laboratory-re-enactment-of-storage-practices-of-older-adults-to-determine-potential-implicat/">laboratory experiment</a>, we also found listeria grows much faster and to significantly greater levels in food when stored in a fridge at 8°C than at 4°C. </p>
<p>So, to avoid listeriosis, use a fridge thermometer to check your fridge is running at a temperature below 5°C. It’s also important to not eat foods that are past their use-by dates. And follow the opened storage duration instructions, for example: “Once opened, consume within two days”.</p>
<p>In contrast, other food poisoning is usually the result of <a href="https://meridian.allenpress.com/jfp/article-abstract/81/4/569/174991/Behavioral-Observation-and-Microbiological?redirectedFrom=fulltext">poor food handling</a> (such as not separating raw and cooked food, or failing to wash hands) that leads to cross-contamination, or failure to cook food to high enough temperatures to reduce the number of bacteria.</p>
<p>The increased cost of food and the rising cost of energy is having a significant <a href="https://www.bbc.co.uk/news/business-61757183">effect on people’s finances</a>. But people could unintentionally put themselves at risk of listeriosis when attempting to reduce their energy usage or spending on food. </p>
<p>For example, people may be more tempted to eat foods beyond their use-by date or keep foods for longer than the recommended duration after opening to avoid wasting food and money. Also, people may be more likely to adjust the temperature of their fridge to reduce electricity usage. </p>
<p>Some people have even said that they might <a href="https://www.bbc.co.uk/news/uk-england-cornwall-62341616">turn off their fridges to save money</a>. Because of this, the UK Health Security Agency has <a href="https://www.bbc.co.uk/news/live/business-62566828?ns_mchannel=social&ns_source=twitter&ns_campaign=bbc_live&ns_linkname=62fcc18a59a1fa43751d087c%26Health+chief+urges+people+to+keep+fridges+on%262022-08-17T12%3A16%3A42.909Z&ns_fee=0&pinned_post_locator=urn%3Aasset%3A43aab261-09b2-4d00-bd69-d420937ab1e5&pinned_post_asset_id=62fcc18a59a1fa43751d087c&pinned_post_type=share&at_custom1=%5Bpost+type%5D&at_campaign=64&at_custom3=%40BBCNews&at_custom2=twitter&at_custom4=1A81F436-1E31-11ED-9E8E-AE4F0EDC252D&at_medium=custom7">urged people to keep fridges on</a> and warned of the risk of food poisoning. </p>
<h2>Best-before v use-by dates</h2>
<p>Many supermarkets have <a href="https://www.theguardian.com/environment/2022/aug/24/asda-scraps-best-before-dates-from-many-fresh-foods-to-help-cut-waste">removed the best-before date</a> from fresh fruit and vegetables. But this doesn’t mean that we don’t need to follow the use-by date. </p>
<p>The best-before date is an indicator of food quality, not safety. In contrast, the use-by date tells us when ready-to-eat and perishable food is safe to eat. The use-by date and opened storage duration instructions are determined through <a href="https://www.campdenbri.co.uk/white-papers/determine-product-shelf-life.php">rigorous microbiological shelf–life testing</a> in food laboratories that establish the point at which levels of bacteria exceed safe limits.</p>
<p>Although many people may be looking at different ways of saving money during this difficult time, we must remember that storing food for too long at the wrong temperature can allow listeria to grow to high numbers, enough to make us ill. </p>
<p>Unfortunately, we can’t see, smell or taste listeria. So ensuring our fridges are running at temperatures below 5°C, and that we follow the use-by dates and the opened storage duration instructions, are essential to protect ourselves and our families from listeria, particularly during the cost of living crisis.</p><img src="https://counter.theconversation.com/content/189417/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ellen W. Evans received funding for research referred to in this article from the Cardiff Metropolitan University Vice Chancellor's Doctoral Award. She is affiliated with the International Association for Food Protection and is past-president of the UK Association for Food Protection. This article refers to research co-authored with Professor Elizabeth C. Redmond.</span></em></p>Food safety experts explain the risks of turning the fridge temperature up (or even turning the fridge off) to save energy.Ellen W. Evans, Research Fellow, ZERO2FIVE Food Industry Centre, Cardiff Metropolitan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1879052022-08-19T12:42:26Z2022-08-19T12:42:26ZWhat is listeria? A microbiologist explains the bacterium behind recent deadly food poisoning outbreaks<figure><img src="https://images.theconversation.com/files/479719/original/file-20220817-21-a18luh.jpg?ixlib=rb-1.1.0&rect=132%2C0%2C3875%2C2951&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Investigators in Florida traced a listeria outbreak to ice cream.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/ice-cream-jar-with-4-flavors-strawberry-vanilla-royalty-free-image/1279372828?adppopup=true">Graiki/Moment via Getty Images</a></span></figcaption></figure><p>Bacteria do, and will, end up in food. Everyone eats – intentionally or unintentionally – <a href="https://doi.org/10.7717/peerj.659">millions to billions</a> of live microbes every day. </p>
<p>Most are completely harmless, but some can cause serious illnesses in humans. Because of these potential pathogens, there is a long <a href="https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/pregnancy-nutrition/art-20043844">list of foods to avoid</a>, including uncooked eggs, raw fish and unwashed fruits and vegetables, particularly for pregnant women. The foods themselves are not bad, but the same cannot be said for certain bacterial passengers, such as <em>Listeria monocytogenes</em>, or listeria for short. </p>
<p>This particular pathogen has found ways to indiscriminately get into our foods. While deli and dairy foods like cold cuts, cheese, milk and eggs are frequently culprits for causing listeriosis – the general name for listeria-caused infections – fresh vegetables and fruits have also been implicated.</p>
<p>The variety of foods responsible for <a href="https://www.cdc.gov/listeria/outbreaks/index.html">U.S. listeria outbreaks in the past decade</a> shows just how easily these bacteria get around. Listeria has turned up in <a href="https://www.cdc.gov/listeria/outbreaks/eggs-12-19/index.html">hard-boiled eggs</a>, <a href="https://www.cdc.gov/listeria/outbreaks/enoki-mushrooms-03-20/index.html">enoki mushrooms</a>, <a href="https://www.cdc.gov/listeria/outbreaks/precooked-chicken-07-21/index.html">cooked chicken</a> and, <a href="https://www.cdc.gov/listeria/outbreaks/packaged-salad-12-21-b/index.html">in 2021, packaged salad</a> – <a href="https://www.cdc.gov/listeria/outbreaks/packaged-salad-mix-12-21/index.html">twice</a>.</p>
<p>Even the frozen aisle is not spared from listeria contamination. Contaminated ice cream in Florida was behind this year’s listeria outbreak, with 25 reported cases spanning 11 states since January 2021, according to <a href="https://www.cdc.gov/listeria/outbreaks/monocytogenes-06-22/details.html">an early August 2022 report</a> from the Centers for Disease Control and Prevention. Those who fell ill ranged in age from less than 1 to 92 years old, and 24 of the cases have involved hospitalizations.</p>
<p>How can such a tiny organism bypass extensive disinfection efforts and wreak such havoc? <a href="https://scholar.google.com/citations?user=G_tH2rUAAAAJ&hl=en">As a microbiologist</a> who has been working with listeria and trying to solve these mysteries, I’d like to share some insider secrets about this unique little pathogen and its strategies of survival inside and outside our bodies.</p>
<h2>Farm to table</h2>
<p>To prevent consumer exposure to listeria, the food industries follow <a href="https://www.fda.gov/files/food/published/Draft-Guidance-for-Industry--Control-of-Listeria-monocytogenes-in-Ready-To-Eat-Foods-%28PDF%29.pdf">stringent disinfection and surveillance guidelines</a> from the Food and Drug Administration and the U.S. Department of Agriculture. Any detection of listeria triggers a recall of potentially contaminated food products. </p>
<p>Since 2017, there have been <a href="https://www.fsis.usda.gov/recalls">over 270 listeria-related food recalls</a>. These are incredibly costly and can sometimes lead to fears in consumers <a href="https://www.npr.org/sections/thetwo-way/2018/01/29/581531318/panera-bread-recalls-cream-cheese-across-u-s-over-listeria-fears">as well as nationwide disruptions in food services</a>. However, the recalls represent one of the few tools that the food industry has to protect consumers from foodborne infections. </p>
<p>Not all listeria strains are created equal. <a href="https://doi.org/10.1016/j.ijmm.2010.05.002">Genetic variations</a> in listeria make a big difference in whether the pathogen ends up being involved in multistate outbreaks or simply hitching a ride harmlessly through our digestive tract. Essentially, based on the <a href="https://doi.org/10.1093/jaoac/85.2.524">different methods used</a>, listeria can be subtyped into different lineages, with some associated with outbreaks more frequently than others.</p>
<p>Researchers are investigating ways to tell these listeria strains apart, distinguishing the less harmful ones from those that are particularly dangerous, or hypervirulent. Being able to accurately identify them can help policymakers assess risks and make economically feasible decisions to improve food safety.</p>
<figure class="align-center ">
<img alt="Illustration of red-orange rod-shaped Listeria bacteria." src="https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C3979&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Listeria is an intracellular pathogen. Inside the body, it can grow inside a cell and spread to neighboring cells.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/listeria-monocytogenes-illustration-royalty-free-illustration/685023881">Kateryna Kon/Science Photo Library via Getty Images</a></span>
</figcaption>
</figure>
<h2>Listeria is tough</h2>
<p>Listeria can live in any place where food is grown, packaged, stored, transported, prepared or served. Our research team has even found listeria in <a href="https://doi.org/10.3390/pathogens7030060">organic lettuce harvested from a backyard garden</a>. </p>
<p>Listeria can survive and grow in temperatures as cold as <a href="https://ask.usda.gov/s/article/Can-Listeria-grow-at-refrigerator-temperatures">24 degrees Fahrenheit</a> (-4.4 Celsius) because it has <a href="https://doi.org/10.1080/10408390701856272">adapted to cold temperatures</a> and developed <a href="https://doi.org/10.4315/0362-028X-69.6.1473">tricks for overcoming cold stress</a>. Considering the average refrigerator maintains a temperature range of 35 F to 38 F (1.7 C to 3.3 C), even when the food is stored properly at refrigeration temperatures, a harmless few listeria can grow to dangerous levels of contamination over time.</p>
<p>Listeria is also extremely versatile in adapting to and surviving all kinds of disinfection processes. When it grows on surfaces, listeria protects itself with <a href="https://doi.org/10.3390%2Fpathogens6030041">a biofilm structure</a>, a kind of coating that forms a physical and chemical barrier and prevents disinfectants from reaching the bacteria within.</p>
<p>Surviving the harsh conditions outside our body is only the first part of the story. Before even beginning to cause infections, listeria needs to get to the intestines without getting caught and destroyed by the body’s defenses.</p>
<p>Traveling and surviving passage through a <a href="https://doi.org/10.3389%2Ffcimb.2014.00009">human digestive tract is not easy</a> for bacteria. Saliva enzymes can degrade bacterial cell walls. So can stomach acids and bile salts. Antibodies in our digestive tract can recognize and target bacteria for degradation. Moreover, <a href="https://doi.org/10.1084%2Fjem.20170495">resident gut microbes</a> are strong competitors for the limited amount of space and nutrients in our intestines.</p>
<p>After digestion, the body’s intestinal movement sends traffic one way – out of the body. In order to stick around and cause infections, bacteria have to attach themselves and hang on against the bowel movement while competing for nutrients. Successful pathogens can establish these survival and attachment tasks while undermining our immune defenses. </p>
<p>Listeria that manage to stick around in our intestines can trigger an immune response. In healthy people, that might manifest as <a href="https://www.cdc.gov/listeria/symptoms.html">minor diarrhea or vomiting that goes away without medical attention</a>. </p>
<p>However, those with compromised immune systems or immune systems temporarily weakened as a result of medication or <a href="https://doi.org/10.3389/fimmu.2020.575197">pregnancy</a> can be more susceptible to severe infections. In the absence of an effective immune system, listeria can invade other tissues and organs by creating an efficient niche for growth.</p>
<h2>Listeria in stealth mode</h2>
<p>Listeria is what we microbiologists call an intracellular pathogen. In an infected individual, listeria can grow inside a cell and <a href="https://doi.org/10.1083%2Fjcb.146.6.1333">spread to neighboring cells</a>. Hiding inside our cells this way, listeria avoids detection by antibodies or other immune defenses that are designed to detect and destroy threats that exist outside of our cells.</p>
<p>Once in stealth mode, listeria can move into and infect different organs. Wherever it goes, inflammation follows as the body’s immune system tries to go after the bacteria. The inflammation eventually results in collateral damage in nearby tissues. </p>
<p>In fact, deaths from listeria infections are often associated with the more invasive forms of the disease in which the microbes have breached the intestinal barriers and moved to other body parts. <a href="https://www.cdc.gov/listeria/symptoms.html">Life-threatening illnesses</a> that can result from listeria include meningitis – inflammation around the brain and spinal cord that can occur when these microbes infect the brain – or <a href="https://doi.org/10.1016/j.ijantimicag.2017.12.032">endocarditis</a>, infection of the heart’s inner lining. And in pregnant individuals, if the pathogen reaches the placenta, it can spread to the fetus and cause stillbirth or miscarriage.</p>
<p>As such, invasive listeria cases often have an alarmingly high <a href="https://www.fda.gov/animal-veterinary/animal-health-literacy/get-facts-about-listeria#">hospitalization rate of more than 90% and a fatality rate that can reach 30%</a>. </p>
<p>The scary statistics argue for a proactive and effective infection control to protect vulnerable populations, such as elderly or pregnant individuals, from listeria exposure. </p>
<h2>Think, cook and eat</h2>
<p>If you have risk factors and want to take extra precautions, maybe turn that unpasteurized cider into a hot, mulled cider to kill the bacteria with boiling and simmering. Eat soft cheeses on foods that get cooked, such as pizzas or grilled sandwiches, instead of eating them cold, straight from the refrigerator. Essentially, use heat to bring out the delicious flavors and eliminate potential listeria contamination in your food. </p>
<p>Ultimately, it’s nearly impossible to live in a completely sterile environment, eating food devoid of all living microorganisms. So enjoy your favorites, but <a href="https://www.fsis.usda.gov/food-safety">stay up to date with ongoing recalls</a> and follow the expiration guidelines, especially for ready-to-eat food.</p><img src="https://counter.theconversation.com/content/187905/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Yvonne Sun does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Listeria causes serious illness and food recalls nearly every year.Yvonne Sun, Assistant Professor of Microbiology, University of DaytonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1856852022-06-29T12:11:35Z2022-06-29T12:11:35ZClimate change is putting food safety at risk more often, and not just at picnics and parties – blackouts are a growing problem<figure><img src="https://images.theconversation.com/files/471485/original/file-20220628-14234-gop3kl.jpg?ixlib=rb-1.1.0&rect=491%2C0%2C4682%2C3086&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Dairy, meats and eggs can get risky when left in warm conditions.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/portrait-of-smiling-boy-holding-sandwich-with-his-royalty-free-image/691049473">Westend61 via Getty Images</a></span></figcaption></figure><p><em>Every year, <a href="https://www.cdc.gov/foodborneburden/2011-foodborne-estimates.html">almost 1 in 6 Americans</a> gets a foodborne illness, and about 3,000 people die from it, according to Centers for Disease Control and Prevention estimates. Picnics and parties where food sits out for hours are a common source, but heat waves and power outages are another silently growing threat.</em></p>
<p><em>As global temperatures rise, the risk of foods going bad during blackouts in homes or stores or during transit in hot weather rises with them. <a href="https://nutrition.tufts.edu/profile/faculty/elena-n-naumova">Elena Naumova</a>, an epidemiologist and data scientist at Tufts University, explains the risk and what you need to know to stay safe.</em></p>
<h2>What does climate change have to do with foodborne illness?</h2>
<p>The link between foodborne illness and climate change is quite straightforward: The pathogens that cause many foodborne infections are sensitive to temperature. That’s because warm, wet weather conditions stimulate bacterial growth.</p>
<p>Three main factors govern the spread of foodborne illness: 1) the abundance, growth, range and survival of pathogens in crops, livestock and the environment; 2) the transfer of these pathogens to food; and 3) human exposure to the pathogens.</p>
<p>Safety measures like warning labels and product recalls can help slow the spread of harmful bacteria and parasites, but these measures don’t always evolve rapidly enough to keep pace with the changing risk.</p>
<p>One growing problem is that heat waves, wildfires and severe storms are increasingly triggering power outages, which in turn affect food storage and food handling practices in stores, production and distribution sites and homes. A review of federal data in 2022 found that major U.S. <a href="https://apnews.com/article/wildfires-storms-science-business-health-7a0fb8c998c1d56759989dda62292379">power outages linked to severe weather had doubled</a> over the previous two decades. California often experiences <a href="https://www.bloomenergy.com/bloom-energy-outage-map/">smaller-scale outages</a> during heat waves and periods of high wildfire risk.</p>
<p>This can happen on the hottest and, in some areas, most humid days, creating ideal conditions for bacteria to grow.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/471456/original/file-20220628-14253-8980uj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/471456/original/file-20220628-14253-8980uj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=503&fit=crop&dpr=1 600w, https://images.theconversation.com/files/471456/original/file-20220628-14253-8980uj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=503&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/471456/original/file-20220628-14253-8980uj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=503&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/471456/original/file-20220628-14253-8980uj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=632&fit=crop&dpr=1 754w, https://images.theconversation.com/files/471456/original/file-20220628-14253-8980uj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=632&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/471456/original/file-20220628-14253-8980uj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=632&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Salmonella bacteria, in pink, a common cause of foodborne disease, invade a human epithelial cell.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/niaid/5613656967">NIAID</a></span>
</figcaption>
</figure>
<h2>Which causes of foodborne illness are increasing with the heat?</h2>
<p>Nationwide, many types of foodborne infection <a href="https://doi.org/10.1038/s41598-020-74435-9">peak in warm summer months</a>.</p>
<p><a href="https://www.cdc.gov/parasites/cyclosporiasis/gen_info/faqs.html"><em>Cyclospora</em></a>, a tiny parasite that causes intestinal infections and is transmitted through food or water contaminated with feces, often on imported vegetables and fruits, peaks in early June. </p>
<p>The bacteria <a href="https://www.cdc.gov/campylobacter/faq.html"><em>Campylobacter</em></a>, a common cause of diarrhea that’s often linked to undercooked meat; <a href="https://www.cdc.gov/vibrio/faq.html"><em>Vibrio</em></a>, linked to eating raw or undercooked shellfish; <a href="https://www.cdc.gov/salmonella/general/index.html"><em>Salmonella</em></a>, which causes diarrhea and is linked to animal feces; and STEC, a common type of <a href="https://www.cdc.gov/ecoli/general/index.html"><em>E. coli</em></a>, peak in mid-July. And the parasite <a href="https://www.cdc.gov/parasites/crypto/index.html"><em>Cyptosporidium</em></a>, germ <a href="https://www.cdc.gov/listeria/faq.html"><em>Listeria</em></a> and bacteria <a href="https://www.cdc.gov/shigella/general-information.html"><em>Shigella</em></a> peak in mid-August.</p>
<p>Many of these infections cause upset stomach, but they can also lead to severe diarrhea, dehydration, vomiting and even longer-term illnesses, such as meningitis and multiple organ failures.</p>
<figure class="align-center ">
<img alt="A man stands in front of a dark freezer case packed with pizzas and other frozen meals." src="https://images.theconversation.com/files/471487/original/file-20220628-14234-33ofq8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/471487/original/file-20220628-14234-33ofq8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=408&fit=crop&dpr=1 600w, https://images.theconversation.com/files/471487/original/file-20220628-14234-33ofq8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=408&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/471487/original/file-20220628-14234-33ofq8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=408&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/471487/original/file-20220628-14234-33ofq8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=513&fit=crop&dpr=1 754w, https://images.theconversation.com/files/471487/original/file-20220628-14234-33ofq8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=513&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/471487/original/file-20220628-14234-33ofq8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=513&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">When refrigerators lose power, they can keep foods cool for only so long. This store owner in New York during the 2006 blackout said, ‘I’ll have to throw all this out.’</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/grocery-store-owener-asim-calik-surveys-a-freezer-full-of-news-photo/71510428">Chris Hondros/Getty Images</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In our studies, my colleagues and I have also found that <a href="https://doi.org/10.3390/ijerph19094947">food recalls increase</a> during summer months. </p>
<p>Typically, the U.S. sees about 70 foodborne outbreaks per month, with about two of them resulting in a food recall. In summer, the number of outbreaks can exceed 100 per month, and the number of recall-related outbreaks goes up to six per month, increasing from 3% to 6% of all reported and investigated outbreaks nationwide. </p>
<p>The rate of individual infections can also <a href="https://doi.org/10.1017/S0950268806006698">easily double or triple</a> the annual average during summer months. </p>
<p><iframe id="JhwJ1" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/JhwJ1/7/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Precisely estimating infection numbers is very challenging because the vast majority of foodborne illness outbreaks – an estimated <a href="https://doi.org/10.1038/s41598-020-74435-9">80% of illnesses and 56% of hospitalizations</a> – are not attributed to known pathogens due to insufficient testing, and many foodborne illnesses are not even reported to the health authorities.</p>
<h2>What types of food should people worry about?</h2>
<p>Watch out for perishable products, including meat, poultry, fish, dairy and eggs, along with anything labeled as requiring refrigeration. How warm a food item can get before becoming risky varies, so the simplest rule for keeping food safe is to follow food labels and instructions.</p>
<p>The <a href="https://www.cdc.gov/foodsafety/index.html%5D(https://www.cdc.gov/foodsafety/index.html">CDC website</a> emphasizes four basic rules to prevent food poisoning at home: clean, separate, cook and chill.</p>
<p>It also offers some guidelines for when the power goes out, starting with keeping refrigerator and freezer doors closed. “A full freezer <a href="https://www.cdc.gov/foodsafety/food-safety-during-a-power-outage.html">will keep food safe for 48 hours</a> (24 hours if half-full) without power if you don’t open the door. Your refrigerator will keep food safe for up to four hours without power if you don’t open the door,” it says.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/471484/original/file-20220628-14613-gop3kl.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An infographic offers advice also discussed in the article." src="https://images.theconversation.com/files/471484/original/file-20220628-14613-gop3kl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/471484/original/file-20220628-14613-gop3kl.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=776&fit=crop&dpr=1 600w, https://images.theconversation.com/files/471484/original/file-20220628-14613-gop3kl.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=776&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/471484/original/file-20220628-14613-gop3kl.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=776&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/471484/original/file-20220628-14613-gop3kl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=976&fit=crop&dpr=1 754w, https://images.theconversation.com/files/471484/original/file-20220628-14613-gop3kl.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=976&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/471484/original/file-20220628-14613-gop3kl.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=976&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Food safety tips.</span>
<span class="attribution"><a class="source" href="https://www.cdc.gov/foodsafety/food-safety-during-a-power-outage.html">CDC</a></span>
</figcaption>
</figure>
<p>After four hours without power or a cooling source, the CDC recommends that most meat, dairy, leftovers and cut fruits and vegetables in the refrigerator be thrown out.</p>
<p>Unfortunately, you cannot see, smell or taste many harmful pathogens that cause foodborne illness, so it’s better to be safe than sorry. Rule of thumb: When in doubt, throw it out.</p>
<h2>What’s the best response if a person gets sick from food?</h2>
<p>If you do get sick, it can be hard to pinpoint the culprit. Harmful bacteria can take anywhere from <a href="https://doh.wa.gov/you-and-your-family/food-safety/food-safety-myths">a few hours to several days</a> to make you sick. And people respond in different ways, so the same food might not make everyone ill.</p>
<p>Check with your doctor <a href="https://www.fda.gov/food/consumers/what-you-need-know-about-foodborne-illnesses">if you think you have food poisoning</a>. Get tested so your case will be reported. That helps public health authorities get a better sense of the extent of infections. The full extent of infections is typically vastly underreported.</p>
<p>I recommend checking health department websites, <a href="https://doh.wa.gov/you-and-your-family/food-safety/food-safety-myths">like Washington state’s</a>, for more advice, and <a href="https://www.fsis.usda.gov/recalls">check on food recalls</a> during the hot months.</p><img src="https://counter.theconversation.com/content/185685/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elena N. Naumova receives funding from the National Science Foundation. She is affiliated with Tufts University. </span></em></p>Climate change has a clear link to rising foodborne illnesses. Blackouts during heat waves and wildfires are a growing part of the problem.Elena N. Naumova, Professor of Epidemiology and Data Science, Tufts UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1808132022-04-14T05:54:03Z2022-04-14T05:54:03ZSurprise! There might be salmonella in your chocolate<figure><img src="https://images.theconversation.com/files/457864/original/file-20220413-9289-ldw894.jpg?ixlib=rb-1.1.0&rect=53%2C8%2C6000%2C3979&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/two-halves-broken-chocolate-egg-children-2126860385">Shutterstock</a></span></figcaption></figure><p>In the past three months, more than <a href="https://www.efsa.europa.eu/en/news/rapid-outbreak-assessment-multi-country-salmonella-outbreak-linked-chocolate-products">150 cases of salmonella food poisoning across Europe</a> have been linked to Kinder chocolate products. Most of the cases have been in children under ten years old.</p>
<p>Health officials have traced the outbreak to <a href="https://abcnews.go.com/Health/wireStory/eu-salmonella-outbreak-chocolate-eggs-due-bad-milk-84031934">bad milk in a factory in Belgium</a>, and many products have been <a href="https://www.foodstandards.gov.au/industry/foodrecalls/recalls/Pages/Kinder-chocolate-products-.aspx">recalled from shelves</a> as Easter approaches.</p>
<p>As consumers, we often think of the risk of food poisoning from raw or under-cooked meat, <a href="https://theconversation.com/christmas-leftovers-how-long-is-it-safe-to-keep-them-84484">leftovers</a> or even <a href="https://theconversation.com/salmonella-in-your-salad-the-cost-of-convenience-54325">packaged salad</a>. It’s less common to worry about chocolate.</p>
<h2>Salmonella outbreaks in chocolate</h2>
<p>While reports of salmonella bacteria in chocolate are not common, there have been several high-profile outbreaks. Most documented cases of salmonellosis have been in Europe and North America, perhaps because chocolate consumption is high and monitoring and surveillance is in place. </p>
<p>Outbreaks include:</p>
<ul>
<li><p>1970: cocoa powder contaminated with salmonella was used in confectionery products and subsequently caused <a href="https://pubmed.ncbi.nlm.nih.gov/4650740/">an outbreak that affected 110 people in Sweden</a></p></li>
<li><p>1973–74: 95 cases of salmonellosis, acquired from Christmas-wrapped chocolate balls, were <a href="https://www.sciencedirect.com/science/article/abs/pii/S031554637573804X">reported in Canada</a> and another 30 in the United States </p></li>
<li><p>1982–83: a salmonella outbreak involving 245 people in the United Kingdom was <a href="https://www.sciencedirect.com/science/article/abs/pii/S0140673683928222">traced to two types of chocolate bars</a> produced in Italy</p></li>
</ul>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/457077/original/file-20220408-20-pb8skx.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/457077/original/file-20220408-20-pb8skx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/457077/original/file-20220408-20-pb8skx.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/457077/original/file-20220408-20-pb8skx.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/457077/original/file-20220408-20-pb8skx.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/457077/original/file-20220408-20-pb8skx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/457077/original/file-20220408-20-pb8skx.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/457077/original/file-20220408-20-pb8skx.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Salmonella outbreaks linked to chocolate.</span>
<span class="attribution"><span class="source">David Bean</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<ul>
<li><p>1985–86: 33 cases of gastroenteritis due to salmonella were <a href="https://meridian.allenpress.com/jfp/article/52/1/51/166460/An-International-Outbreak-of-Salmonella-Nima-from">reported in Canada and the US</a>, and eventually traced back to chocolate coins imported from Belgium</p></li>
<li><p>1987: 361 confirmed cases of salmonellosis in Norway and Finland were <a href="https://journals.asm.org/doi/abs/10.1128/jcm.28.12.2597-2601.1990">part of an outbreak</a> linked to chocolate contaminated with salmonella (it is estimated the actual number of infections was 20,000-40,000)</p></li>
<li><p>2001–02: an outbreak of salmonella occurred in Germany, resulting in<a href="https://bmcinfectdis.biomedcentral.com/articles/10.1186/1471-2334-5-7"> at least 439 reports of infection</a>, traced to a specific brand of chocolate distributed exclusively through a single supermarket chain</p></li>
<li><p>2006: an outbreak in the UK was <a href="https://www.eurosurveillance.org/content/10.2807/esw.11.26.02985-en">traced to chocolate</a>, with 56 cases reported.</p></li>
</ul>
<h2>Why do salmonella outbreaks occur?</h2>
<p>Chocolate begins its life as various agricultural products, the most important of which is cacao. Much of the world’s cacao comes from small farms in West Africa. </p>
<p>Beans from the cacao tree are harvested, fermented and dried on these farms. There are plenty of opportunities for the beans to become contaminated with salmonella from animals and the environment.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/salmonella-in-your-salad-the-cost-of-convenience-54325">Salmonella in your salad: the cost of convenience?</a>
</strong>
</em>
</p>
<hr>
<p>When the beans reach a chocolate factory, they are roasted. This will kill any salmonella on the beans. But if salmonella is present on the raw beans it can potentially be a source of contamination. </p>
<p>It is important raw beans are well segregated from roast beans to prevent cross-contamination. </p>
<p>As well as this segregation, chocolate factories must be well maintained and have risk-control mechanisms in place. The 2006 outbreak in the UK, for example, was ultimately linked to <a href="https://www.confectionerynews.com/Article/2006/08/02/Cadbury-contamination-proves-costly">water leaks from pipes onto chocolate</a>.</p>
<h2>Salmonella in chocolate</h2>
<p>Even when chocolate is made using appropriate food safety techniques, it has inherent properties that make it <a href="https://link.springer.com/chapter/10.1007/978-1-4939-2062-4_14">very capable of spreading bacteria</a>. </p>
<p>While salmonella will not <em>grow</em> in chocolate (there isn’t enough water), it <em>survives</em> in chocolate very well. Chocolate may even protect the salmonella during its passage through the gut. </p>
<figure class="align-center ">
<img alt="A photograph of a person pouring molten chocolate from a pot into a tray." src="https://images.theconversation.com/files/457869/original/file-20220413-9145-hvp86m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/457869/original/file-20220413-9145-hvp86m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/457869/original/file-20220413-9145-hvp86m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/457869/original/file-20220413-9145-hvp86m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/457869/original/file-20220413-9145-hvp86m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/457869/original/file-20220413-9145-hvp86m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/457869/original/file-20220413-9145-hvp86m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Salmonella won’t grow in chocolate, but it survives there very well.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/production-cooking-people-concept-confectioner-filling-1283944153">Shutterstock</a></span>
</figcaption>
</figure>
<p>This means a batch of chocolate product contaminated with salmonella may remain a food safety risk for a long time and be distributed over a large geographical area. This explains why chocolate-related outbreaks can affect large numbers of people in multiple countries.</p>
<p>Another important consideration is who often consumes chocolate: children. Children are often disproportionately represented in these outbreaks and may be more susceptible to severe infections.</p>
<h2>What can be done?</h2>
<p>Most confectionery manufacturers operate under stringent guidelines to ensure quality and safety of their products. Good manufacturing processes and food safety guidelines are well established to ensure chocolate is safe. </p>
<p>Manufacturers would prefer to eliminate pathogens (disease causing microorganisms) such as salmonella in chocolate, or at least detect it during manufacturing. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/christmas-leftovers-how-long-is-it-safe-to-keep-them-84484">Christmas leftovers: how long is it safe to keep them?</a>
</strong>
</em>
</p>
<hr>
<p>However, the current Kinder recall and others like it are evidence of the system working, albeit late in the process. When a recall notice is issued, consumers should take the advice seriously.</p>
<p>So don’t put off a little Easter indulgence! In the absence of a recall notice in a specific product, it is safe to assume eating chocolate won’t make you sick – unless perhaps you over-indulge.</p><img src="https://counter.theconversation.com/content/180813/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>I previously worked at Mars as a Global Microbiology Food Safety Manager.</span></em></p><p class="fine-print"><em><span>Andrew Greenhill does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Despite the recent Kinder chocolate recall, there’s no cause for wider concern about chocolate safety.David Bean, Senior Lecturer in Microbiology, Federation University AustraliaAndrew Greenhill, Associate Professor in Microbiology and Fermentation Technology, Federation University AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1795902022-03-25T11:28:12Z2022-03-25T11:28:12ZThe dangers of eating raw meat<figure><img src="https://images.theconversation.com/files/453023/original/file-20220318-13-f1w6ml.jpg?ixlib=rb-1.1.0&rect=11%2C11%2C7337%2C4891&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/handsome-man-biting-raw-meat-on-566969275">RossHelen/Shutterstock</a></span></figcaption></figure><p>Rising energy and gas prices might make you think twice about firing up your stove for a roast or stew. Why cook that meat? After all, your menu could include trendy beef carpaccio, flavoursome wild boar’s liver, coppa or pancetta. If you learned to like raw meat, you might become a paleo-keto-carnivorous pilgrim, with visions of developing a <a href="https://www.dailymail.co.uk/femail/article-10620271/Fitness-coach-reveals-eats-raw-meat-including-brains-testicles-day.html">ripped torso</a>. </p>
<p>Humans are omnivores: we can digest raw meat and thrive. The Inuit, among others living in frozen latitudes, <a href="https://www.nationalgeographic.org/photo/blubber-inuitgirl-743-60352/">eat raw meat</a> from seals, caribou, elk or whale. Uncooked cuts from <a href="https://www.atlasobscura.com/foods/basashi-horse-meat">horses</a>, <a href="https://www.tasteatlas.com/torisashi">chickens</a> and goats are presented as small delicacies on tables from Europe to Japan. While some <a href="https://www.news.com.au/lifestyle/food/eat/bodybuilder-brian-johnson-swears-by-gross-raw-meat-diet/news-story/5e0c53e1c83a7931db08537f95d02754#:%7E:text=Bodybuilder%20Brian%20Johnson%20swears%20by%20a%20diet%20of%20raw%20liver,meals%20with%20thousands%20of%20followers.&text=A%20man%20who%20swears%20by,and%20bone%20marrow%20every%20day.">bodybuilders promote raw meat</a> and offal diets (carefully selected). </p>
<p>Raw meat has also been used as medicine. In the late 19th century, French doctors suggested it as a <a href="https://www.scientificamerican.com/article/meat-pills-fight-tuberculosis/">treatment for tuberculosis</a>. It seemed successful, sometimes. But the researchers described two problems. First, obtaining clean raw meat was difficult. Second, their patients disliked their daily dose of half a pound of raw meat. Treatments were adjusted to using the meat juice instead. This “zomotherapy” was more popular and, they said, less likely to cause tapeworm infections. </p>
<p>Raw liver therapy for pernicious anaemia <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2376267/">was investigated by George Minot and William Murphy</a>. They received the Nobel prize in 1934 for this pioneering work that paved the way to isolating vitamin B12. B12 is stored in a herbivore’s liver and damaged by cooking. These early studies all showed that raw meat came with some dangers from infection and infestation. </p>
<figure class="align-center ">
<img alt="Inuit elders eating muktuk (raw whale skin and blubber)." src="https://images.theconversation.com/files/454219/original/file-20220324-15-1vqbj48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454219/original/file-20220324-15-1vqbj48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=410&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454219/original/file-20220324-15-1vqbj48.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=410&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454219/original/file-20220324-15-1vqbj48.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=410&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454219/original/file-20220324-15-1vqbj48.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=515&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454219/original/file-20220324-15-1vqbj48.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=515&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454219/original/file-20220324-15-1vqbj48.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=515&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Inuit elders eating muktuk (raw whale skin and blubber).</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/w/index.php?curid=787741">Ansgar Walk/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Microbial hazards</h2>
<p>The animals we eat share this planet with us. We are all surrounded by an amazing diversity of uncountable microbes, some of which may be shared at mealtimes. A tempting piece of raw meat, therefore, requires elaborate checking. Has it any prions, viruses, bacteria, fungi or parasites? </p>
<p>Although many of these critters are harmless, some are quite lethal unless treated. Some, such as prion-linked brain diseases, <a href="https://pubmed.ncbi.nlm.nih.gov/24956437/">cannot be treated</a>. And some will treat us as <em>their</em> food. If that steak is venison from your recent hunt, its pathogens will be different compared to a farm-reared steer. </p>
<p>The bacteria <em>Escherichia coli</em>, for example, were thought harmless when described in 1885. Up to 50% of healthy cattle may carry <em>E. coli 0157</em>. These are resistant to our stomach acid; their Shiga toxins can cause <a href="https://www.nhsinform.scot/illnesses-and-conditions/infections-and-poisoning/escherichia-coli-e-coli-o157">kidney failure, shock and death</a>.</p>
<p>Listeria is named after Joseph Lister, the father of surgical sterilisation. It is a skilled soil organism that can multiply on a steak in your fridge, then infect your bloodstream and brain, or cross a placenta resulting in miscarriage and foetal death.</p>
<p>Beef can be contaminated with <em>Toxoplasmosis gondii</em>, a protozoal parasite from cats that happily survives in cattle and humans. <a href="https://theconversation.com/toxoplasma-cat-poo-parasite-infects-billions-so-why-is-it-so-hard-to-study-120688">Toxoplasmosis</a> tends to find its way into the brain, retina, heart muscle or cross the placenta, where it can damage the foetal brain. Some of these effects may take years to become evident; you would probably not notice anything after that raw lunch.</p>
<p>Although there are no proven advantages to eating raw meat, there are great microbial hazards. (Feeding your pets raw meat has <a href="https://theconversation.com/should-you-feed-your-pet-raw-meat-the-real-risks-of-a-traditional-dog-diet-90271">similar risks</a>.) Not only is there a risk of being infected with <em>Campylobacters</em> and <em>Salmonellas</em>, but also parasites such as roundworms and tapeworms.</p>
<p>The passion – in some quarters – for returning to a habit of consuming raw meat should be checked against the facts of “<a href="https://theconversation.com/one-health-a-crucial-approach-to-preventing-and-preparing-for-future-pandemics-173637">one health</a>” – that is, taking into consideration the combined health of people, animals and our environments. We are not alone. Many, many microbes, usually checked by safe food management and cooking, would just love us to take up a wolverine lifestyle.</p><img src="https://counter.theconversation.com/content/179590/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Colin Michie does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Some ‘influencers’ are pushing a raw-meat diet. Here’s why you should avoid it.Colin Michie, Deputy Lead, School of Medicine, University of Central LancashireLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1738792022-02-14T13:22:23Z2022-02-14T13:22:23ZWhy do people get diarrhea?<figure><img src="https://images.theconversation.com/files/442542/original/file-20220125-23-5eakbl.jpg?ixlib=rb-1.1.0&rect=0%2C519%2C5058%2C2800&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">No matter its cause, diarrhea is uncomfortable.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/man-holding-toilet-tissue-roll-in-bathroom-royalty-free-image/1249645235">Rapeepong Puttakumwong/Moment via Getty Images</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
<hr>
<blockquote>
<p><strong>Why do people get diarrhea? – A.A.A., age 10, Philadelphia</strong></p>
</blockquote>
<hr>
<p>The digestive system breaks down everything you eat and drink to absorb nutrients and make the energy your body needs. Whatever solids can’t be broken down and used get <a href="https://www.ncbi.nlm.nih.gov/books/NBK539732/">excreted as poop</a>.</p>
<p>Poop comes in many shapes, sizes, colors and consistencies.</p>
<p><a href="https://scholar.google.com/citations?user=mHFFJtUAAAAJ&hl=en&oi=ao">Doctors like me</a> who treat people with digestive issues use what’s called the <a href="https://dx.doi.org/10.1016%2Fj.jpeds.2011.03.002">Bristol stool scale</a> to grade poop texture. It goes from Type 1 – separate hard lumps – to Type 7 – liquid with no solid pieces. The texture of the best poops, Type 4, resembles a mushy banana.</p>
<p>When your <a href="https://blog.katescarlata.com/2021/04/19/common-disorders-associated-with-diarrhea/">poop is loose and watery</a> and comes out that way at least three times a day, you have <a href="https://www.who.int/news-room/fact-sheets/detail/diarrhoeal-disease">diarrhea</a>. It can be uncomfortable and inconvenient, because diarrhea tends to come out quickly and with little warning. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration of the seven categories of poop, ranging from overly firm to liquid." src="https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/442540/original/file-20220125-15-n9shj2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Bristol stool scale puts poop into seven categories that range from the hard pellets of constipation to the splotchy liquid of diarrhea.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/bristol-stool-chart-tool-for-faeces-type-royalty-free-illustration/1250463401">VectorMine/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<h2>Beware of bad germs</h2>
<p>By the time food passes out of the stomach, it’s a liquid that travels through the small intestine, where nutrients are absorbed. The leftovers flow into the large intestine, where water is absorbed and poop forms.</p>
<p>When the small intestine or the large intestine can’t do its job, poop will be liquid. </p>
<p>Diarrhea usually occurs because of infections caused by many different <a href="https://www.doi.org/10.4161/gmic.1.1.11036">viruses, bacteria and parasites</a>.</p>
<p>That’s why there are <a href="https://www.epa.gov/dwreginfo/drinking-water-regulations">rules about keeping drinking water clean</a> and <a href="https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/steps-keep-food-safe">food safe</a>. It’s also why you should wash your hands before eating. </p>
<p>These germs cause diarrhea a few different ways. Often, they irritate the intestines, interfering with water absorption. Some germs cause diarrhea by <a href="https://www.mayoclinic.org/diseases-conditions/cholera/symptoms-causes/syc-20355287">releasing chemicals</a> that make the intestines release fluid, making poop even more watery. When these <a href="https://www.cdc.gov/foodsafety/foodborne-germs.html">germs come from food</a>, symptoms can include vomiting, belly pain and diarrhea.</p>
<p>To be sure, not all microbes are bad.</p>
<p>In fact, your <a href="https://doi.org/10.1038/nature11053">digestive system is filled with billions of bacteria</a> and other germs that help you digest food and protect you from bad germs. <a href="https://doi.org/10.2217/17460913.3.5.563">Taking antibiotics for an infection can cause diarrhea</a> by killing off these good bacteria along with the ones that originally made you sick. But people usually get better once they finish prescribed antibiotics and the good bacteria have a chance to recover.</p>
<p>People with diarrhea need to consume lots of liquids to stay hydrated. Water is best. Avoid <a href="https://doi.org/10.1001/archpedi.1985.02140070077039">juice</a> and <a href="https://irritablebowelsyndrome.net/food/no-soda">soda</a>, which can worsen diarrhea. Also refrain from foods that can make your digestive system work harder, like dairy products.</p>
<p><a href="https://www.childrens.com/health-wellness/how-to-treat-diarrhea-in-kids">Eating sweet potatoes, oats, beets</a> and other high-fiber foods may help firm up loose poops. Never take a medication, even if doesn’t require a prescription, for diarrhea without asking a doctor first. </p>
<h2>Many other causes</h2>
<p>There are many other causes of diarrhea.</p>
<p>Some people are born with or develop conditions over the course of their lives that can cause diarrhea.</p>
<p>A common example is <a href="http://dx.doi.org/10.1136/gutjnl-2019-318404">lactose intolerance</a>. Lactose is a sugar that is in milk that requires a <a href="https://www.britannica.com/science/lactase">special enzyme, called lactase</a>, to digest it in the small intestine. There are people who have little, or even none, of this enzyme in their small intestine. As a result, lactose travels into their large intestine without being broken down and absorbed – leaving poop very runny.</p>
<p><a href="https://doi.org/10.3389/fped.2018.00350">Celiac disease</a> can also trigger diarrhea. People with it have <a href="https://www.health.harvard.edu/healthbeat/getting-out-the-gluten">trouble digesting gluten</a>, a protein found in wheat and additional grains. For people with celiac disease, eating gluten can damage the small intestine by activating their own immune system. This damage is reversible through a gluten-free diet, but diarrhea may continue until the small intestine heals and can do its job.</p>
<p>Others have <a href="https://doi.org/10.3389/fmed.2017.00261">digestive system allergies</a>. They need to avoid eating specific foods to prevent diarrhea and other symptoms. </p>
<p>Some medications make you poop more often.</p>
<p>There are also medical conditions, like <a href="https://doi.org/10.1053/j.gastro.2021.04.063">inflammatory bowel disease</a>, such as <a href="https://www.mayoclinic.org/diseases-conditions/crohns-disease/symptoms-causes/syc-20353304">Crohn’s disease</a> and <a href="https://www.mayoclinic.org/diseases-conditions/ulcerative-colitis/symptoms-causes/syc-20353326">ulcerative colitis</a>, in which the small intestine, large intestine or both become inflamed over a period of time.</p>
<p>Even your brain can play a role: Experiencing anxiety or <a href="https://www.healthline.com/health/anxiety-diarrhea">getting stressed out</a> can bring about loose poops. Some conditions, like <a href="https://doi.org/10.14309/ajg.0000000000001036">irritable bowel syndrome</a>, where the brain and the intestines do not communicate well with each other, can lead to belly pain and diarrhea, particularly amid stress. </p>
<p><a href="https://www.mayoclinic.org/diseases-conditions/cancer/in-depth/diarrhea/art-20044799">Certain cancers</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6867674/">some tumors</a> can cause diarrhea too. </p>
<p>Finally, for some people, eating spicy or fatty food or consuming artificial sweeteners or <a href="https://www.healthline.com/health/foods-that-cause-diarrhea#food-and-diarrhea">large amounts of caffeine</a> can result in diarrhea. </p>
<p>Even if you find it icky, I recommend you pay attention to your poop. If you’re having diarrhea all the time, rather than occasionally, you may need to see a doctor.</p>
<hr>
<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/173879/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hannibal Person does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Poop comes in many shapes, sizes and textures. The kind that’s too runny might be the result of wayward germs, Crohn’s disease or lactose intolerance.Hannibal Person, Assistant Professor of Gastroenterology and Hepatology, School of Medicine, University of WashingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1531852021-07-21T12:05:03Z2021-07-21T12:05:03ZHow to avoid food-borne illness – a nutritionist explains<figure><img src="https://images.theconversation.com/files/403014/original/file-20210527-16-cagjpk.jpg?ixlib=rb-1.1.0&rect=15%2C23%2C5196%2C3446&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">After the meal, putting food away quickly is key to keeping it free from pathogens.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/overhead-view-of-friends-dining-at-table-outdoors-royalty-free-image/126364029?adppopup=true">Getty Images / Thomas Barwick</a></span></figcaption></figure><p>Summer means cookouts, picnics and backyard barbecues. But a generous spread of food eaten outside raises some serious health questions. Nobody wants food poisoning – or to make their guests sick. But how do you know when you’ve kept the potato salad or fruit medley out too long? </p>
<p><a href="https://scholar.google.com/citations?user=vH4quSQAAAAJ&hl=en">As a professor and chair</a> of the Food Science and Human Nutrition program at Iowa State University, I’ll answer those questions by starting with the basics of food safety. </p>
<p>Two general classes of food-related microorganisms exist. Pathogenic organisms make you sick. Other types of organisms make food look, smell and taste bad – in other words, they make food spoil. </p>
<p>It’s usually pretty easy to tell if spoilage microorganisms have invaded your food. <a href="https://www.healthline.com/nutrition/is-moldy-food-dangerous#:%7E:text=Food%20spoilage%20is%20often%20caused,certain%20foods%2C%20including%20some%20cheeses">Molds and fuzzy growth</a> appear on solid foods. Liquids look cloudy or clumpy and often smell bad. Eating spoiled foods is never a good idea, and you’re smart to err on the side of caution. When in doubt, throw it out. </p>
<figure class="align-center ">
<img alt="A cook cutting vegetables on a cutting board." src="https://images.theconversation.com/files/403047/original/file-20210527-23-stugy8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/403047/original/file-20210527-23-stugy8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/403047/original/file-20210527-23-stugy8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/403047/original/file-20210527-23-stugy8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/403047/original/file-20210527-23-stugy8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/403047/original/file-20210527-23-stugy8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/403047/original/file-20210527-23-stugy8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Don’t use the same cutting board for meat and vegetables.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/preparing-julienned-vegetables-for-korean-pancakes-royalty-free-image/980099930?adppopup=true">Getty Images / Enrique Díaz / 7cero</a></span>
</figcaption>
</figure>
<h2>Cutting boards and kitchen thermometers</h2>
<p><a href="https://www.healthline.com/health/what-is-a-pathogen#types">Pathogenic microorganisms</a> in foods are much more stealthy. These microorganisms are the ones that cause cramps, vomiting, diarrhea, fever and chills – symptoms that people associate with the “stomach flu.” Viruses also cause food-borne illness. Typically, detecting pathogens in foods by smell or sight isn’t possible. So proper handling and storage, and knowing when to toss leftovers, is critical. </p>
<p>The first rule of food safety is to keep preparation areas clean. Developing a routine helps. Always wash your hands before handling food. Make sure you thaw meats in the refrigerator, not on the countertop. Otherwise, as the frozen meat sits at room temperature, its outer surfaces warm faster than the interior. This allows pathogens to multiply. </p>
<p>Don’t use the same cutting board for meat, fruits and vegetables. In my kitchen, a red cutting board is for meat; the green one for fruits and vegetables. Use different knives, plates and utensils for the raw meats, and always put cooked meats on a clean plate. </p>
<p>Never rinse off raw meat or chicken in the sink, because that practice spreads bacteria on kitchen surfaces. Actually, <a href="https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/washing-food-does-it-promote-food">there’s no need to rinse meat and chicken</a> before cooking. But, if you insist, sanitize the sink with an antibacterial cleaning after moving the food away. That’s “after” – be sure not to contaminate any foods with the cleaner. </p>
<p>Any pathogens will be destroyed by fully cooking the meat to the recommended temperatures. Invest in a good kitchen thermometer. <a href="https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/safe-temperature-chart">Although recommendations can vary slightly</a>, you basically want an internal temperature of 160 F (71 C) for beef and pork, 165 F (74 C) for poultry, and 145 F (63 C) for fish and ham. Once food is cooked, keep hot foods at 140 F (60 C) or higher. When transporting or serving foods over a period of time, keep cold foods on ice or in a cooler, especially during the hot summer months.</p>
<figure class="align-center ">
<img alt="A man takes leftovers out of the refrigerator." src="https://images.theconversation.com/files/403049/original/file-20210527-19-1tfwn3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/403049/original/file-20210527-19-1tfwn3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/403049/original/file-20210527-19-1tfwn3b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/403049/original/file-20210527-19-1tfwn3b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/403049/original/file-20210527-19-1tfwn3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/403049/original/file-20210527-19-1tfwn3b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/403049/original/file-20210527-19-1tfwn3b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Don’t let leftovers stay in the refrigerator too long.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/man-looking-at-leftovers-in-refrigerator-royalty-free-image/85651072?adppopup=true">Getty Images / Jupiterimages</a></span>
</figcaption>
</figure>
<h2>Dealing with leftovers</h2>
<p>After the meal is over, don’t let the leftovers linger. Move them into the refrigerator quickly. </p>
<p>As a newlywed, I spent Thanksgiving at my in-laws’ home in northern Minnesota. After dinner, they took all the serving dishes – turkey, stuffing and mashed potatoes – and put them on the screened porch for storage. It was probably less than 20 F (-6 C) degrees outside – but still, that’s not a great idea because weather changes quickly and temperatures will fluctuate, leading to risk of pathogen growth. </p>
<p>My husband also believed foods should cool down on the counter before putting them in the fridge; he said it reduced stress on the refrigerator. This is not necessary and increases the risk for food pathogens. Modern refrigerators are fully capable of cooling warm foods quickly <a href="https://www.fda.gov/food/people-risk-foodborne-illness/tips-chill-food-food-safety-moms-be">while maintaining their internal temperatures</a>, so don’t hesitate to put away those leftovers as soon as possible.</p>
<p>Now, with the fridge full of leftovers, <a href="https://www.usda.gov/media/blog/2018/11/23/thanksgiving-leftovers-safe-keeping-weekend-grazing">how long are they good to eat</a>? Most cooked foods are safe to consume within three to four days. After that, contamination risk increases. If you have more leftovers than you can eat in that time frame, put them in the freezer. Be sure to cook leftovers to 165 F (74 C) before eating.</p>
<p>Baked goods like breads, cakes, pies and cookies made in your kitchen will have a shorter shelf life than store-purchased items because yours are <a href="https://www.fda.gov/food/food-ingredients-packaging/overview-food-ingredients-additives-colors">without preservatives</a>. They will become stale, lose their texture sooner and grow mold. Once you see that, toss the whole thing out rather than try to cut away the contaminated spots. While it’s unlikely to cause severe illness, <a href="https://www.who.int/news-room/fact-sheets/detail/mycotoxins">some bread molds produce toxins</a> that might cause problems, particularly for children or the elderly.</p>
<p>Foods with higher moisture content <a href="https://www.eatthis.com/foods-that-spoil-fastest/">spoil faster</a> because water gives bacteria a chance to grow. So carrot cakes or zucchini bread spoil within about five days. Refrigerate these items, and you’ll increase their shelf life. Pies should be stored in the refrigerator and eaten within three to four days. Cookies are typically low in moisture, except those containing fruit, jam or icing. Keep these types of cookies in the refrigerator and discard if they start to grow mold. </p>
<p>As you get ready for your summer get-togethers, keep in mind that reducing food waste is good for both the environment and your budget, so consider portion sizes and the quantity you’re making to better manage leftovers. And remember that proper handling as you prepare and then store your meals will make sure you and your family enjoy your cookouts, parties and reunions without a food-related illness. </p>
<p>[<em>Understand new developments in science, health and technology, each week.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-understand">Subscribe to The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/153185/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ruth S. MacDonald does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>‘When in doubt, throw it out’ – and more tips to make sure your festive feast won’t make you sick.Ruth S. MacDonald, Associate Dean, College of Agriculture and Life Sciences, Iowa State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1554432021-02-22T13:26:06Z2021-02-22T13:26:06ZHow safe is your baby food?<figure><img src="https://images.theconversation.com/files/385363/original/file-20210219-19-p33c1o.jpg?ixlib=rb-1.1.0&rect=92%2C423%2C4552%2C2996&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">One study found that 95% of baby foods tested contained at least one heavy metal.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/baby-being-fed-royalty-free-image/522813035">Plume Creative via Getty Images</a></span></figcaption></figure><p>Heavy metals including lead, arsenic and mercury can be found in commercial baby foods at levels well above what the federal government considers safe for children, a new <a href="https://oversight.house.gov/sites/democrats.oversight.house.gov/files/2021-02-04%20ECP%20Baby%20Food%20Staff%20Report.pdf">congressional report</a> warns.</p>
<p>Members of Congress asked seven major baby food makers to hand over test results and other internal documents after a <a href="https://www.healthybabyfood.org/sites/healthybabyfoods.org/files/2019-10/BabyFoodReport_FULLREPORT_ENGLISH_R5b.pdf">2019 report</a> found that, out of 168 baby food products, 95% contained at least one heavy metal. Foods with rice or root vegetables, like carrots and sweet potatoes, had some of the highest levels, but they weren’t the only ones. </p>
<p>How concerned should parents be and what can they do to reduce their child’s exposure?</p>
<p>As a professor and pharmacist, I have investigated health safety concerns for several years <a href="https://doi.org/10.1177/1060028019881692">in drugs</a> and <a href="https://doi.org/10.1177/1060028019900504">dietary supplements</a>, including contamination with heavy metals and the chemical <a href="http://doi.org/10.1001/jamanetworkopen.2020.35158">NDMA</a>, a likely carcinogen. Here are answers to four questions parents are asking about the risks in baby food.</p>
<h2>How do heavy metals get into baby food?</h2>
<p>Heavy metals come from the natural erosion of the <a href="http://doi.org/10.1155/2011/870125">Earth’s crust</a>, but humans have dramatically accelerated environmental exposure to heavy metals, as well. </p>
<p>As <a href="https://www.eia.gov/energyexplained/coal/coal-and-the-environment.php">coal</a> is burned, it releases heavy metals into the air. Lead was commonly found in gasoline, paint, pipes and pottery glazes for decades. A pesticide with both <a href="http://doi.org/10.1289/ehp.114-a470">lead and arsenic</a> was widely used on crops and in orchards until it was banned in 1988, and phosphate-containing fertilizers, including organic varieties, still contain small amounts of <a href="https://doi.org/10.1007/BF00747683">cadmium, arsenic, mercury and lead.</a> </p>
<p>These heavy metals still contaminate soil, and irrigation can expose more soil to heavy metals in water.</p>
<p>When food is grown in contaminated soil and irrigated with water containing heavy metals, the food becomes contaminated. Additional heavy metals can be introduced during manufacturing processes.</p>
<p>The United States has made major strides to reduce the use of fossil fuels, filter pollutants and remove lead from many products such as gasoline and paint. This reduced exposure to <a href="https://www.epa.gov/air-trends/lead-trends">lead in the air</a> by 98% from 1980 to 2019. Processes can now also remove a proportion of the heavy metals from <a href="http://doi.org/10.1016/j.chemosphere.2019.04.198">drinking water</a>. However, the heavy metals that accumulated in the soil over the decades is an ongoing problem, especially in <a href="http://doi.org/10.1021/es400521h">developing countries</a>. </p>
<h2>How much heavy metal is too much?</h2>
<p>The <a href="https://apps.who.int/food-additives-contaminants-jecfa-database/search.aspx">World Health Organization</a> and the <a href="https://www.fda.gov/food/metals-and-your-food/survey-data-lead-womens-and-childrens-vitamins">Food and Drug Administration</a> have defined tolerable daily intakes of heavy metals. However, it’s important to recognize that for many heavy metals, including lead and arsenic, there is no daily intake that is completely devoid of long-term health risk.</p>
<p>For lead, the FDA considers 3 micrograms per day or more to be cause for concern <a href="https://www.fda.gov/food/metals-and-your-food/lead-food-foodwares-and-dietary-supplements">in children</a>, well below the level for adults (12.5 micrograms per day).</p>
<p>Young children’s bodies are smaller than adults, and lead can’t be <a href="http://doi.org/10.1515/intox-2015-0009">stored as readily in the bone</a>, so the same dose of heavy metals causes much greater blood concentrations in young children where it can do more damage. In addition, young brains are more rapidly developing and are therefore at greater risk of neurological damage.</p>
<figure class="align-center ">
<img alt="Baby food jars" src="https://images.theconversation.com/files/385364/original/file-20210219-23-8bp35z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/385364/original/file-20210219-23-8bp35z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=404&fit=crop&dpr=1 600w, https://images.theconversation.com/files/385364/original/file-20210219-23-8bp35z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=404&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/385364/original/file-20210219-23-8bp35z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=404&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/385364/original/file-20210219-23-8bp35z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=507&fit=crop&dpr=1 754w, https://images.theconversation.com/files/385364/original/file-20210219-23-8bp35z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=507&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/385364/original/file-20210219-23-8bp35z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=507&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Root vegetables, such as sweet potatoes and carrots, have some of the highest levels of heavy metals.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/hand-spooning-baby-food-royalty-free-image/95468925">Tetra Images via Getty Images</a></span>
</figcaption>
</figure>
<p>These lead levels are <a href="https://www.fda.gov/food/metals-and-your-food/lead-food-foodwares-and-dietary-supplements">about one-tenth</a> of the dose needed to achieve a blood lead concentration associated with major neurological problems, including the development of behavioral issues like aggression and attention deficit disorder. That doesn’t mean lower doses are safe, though. Recent research shows that <a href="http://doi.org/10.1515/intox-2015-0009">lower blood lead levels</a> still impact neurological function, just not as dramatically.</p>
<p>For other heavy metals, the daily intake considered tolerable is based on <a href="https://apps.who.int/food-additives-contaminants-jecfa-database/search.aspx">body weight</a>: mercury is 4 micrograms per kilogram of body weight; arsenic is not currently defined but before 2011 it was 2.1 micrograms per kilogram of body weight. </p>
<p>Like with lead, there is a considerable safety margin between the tolerable dose and the dose that poses high risk of causing neurological harm, <a href="http://doi.org/10.1515/intox-2015-0009">anemia</a>, <a href="http://doi.org/10.1155/2011/870125">liver and kidney damage and an increased risk of cancer</a>. But even smaller amounts still carry risks.</p>
<p>One example of the exposure infants can face is a <a href="https://www.healthybabyfood.org/sites/healthybabyfoods.org/files/2019-10/BabyFoodReport_FULLREPORT_ENGLISH_R5b.pdf">brand of carrot baby food</a> found to have 23.5 parts of lead per billion, <a href="http://www.endmemo.com/sconvert/ppbug_g.php">equivalent</a> to 0.67 micrograms of lead per ounce. Since the average 6-month-old eats 4 ounces of vegetables a day, that would be 2.7 micrograms of lead a day – almost the maximum tolerable daily dose.</p>
<h2>What can parents do to reduce a child’s exposure?</h2>
<p>Since the amount of heavy metals varies so dramatically, food choices can make a difference. Here are a few ways to reduce a young child’s exposure.</p>
<p>1) Minimize the use of <a href="https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-action-level-inorganic-arsenic-rice-cereals-infants?">rice-based products</a>, including rice cereal, puffed rice and rice-based teething biscuits. Switching from rice-based products to those made with oats, corn, barley or quinoa could reduce the ingestion of arsenic by 84% and total heavy metal content <a href="https://www.healthybabyfood.org/sites/healthybabyfoods.org/files/2019-10/BabyFoodReport_FULLREPORT_ENGLISH_R5b.pdf">by about 64%</a>, according to the study of 168 baby food products by the group Healthy Babies Bright Futures.</p>
<p>Using frozen banana pieces or a clean washcloth instead of a rice cereal based teething biscuit was found to reduce the total heavy metal exposure <a href="https://www.healthybabyfood.org/sites/healthybabyfoods.org/files/2019-10/BabyFoodReport_FULLREPORT_ENGLISH_R5b.pdf">by about 91%</a>.</p>
<p>2) Switch from fruit juices to water. Fruit juice is not recommended for small children because it is laden with sugar, but it also is a source of heavy metals. Switching to water could reduce the intake of heavy metals <a href="https://www.healthybabyfood.org/sites/healthybabyfoods.org/files/2019-10/BabyFoodReport_FULLREPORT_ENGLISH_R5b.pdf">by about 68%</a>, according to the report.</p>
<p>3) Alternate between root vegetables, such as carrots and sweet potatoes, and other vegetables. The roots of plants are in closest contact with the soil and have higher concentrations of heavy metals than other vegetables. Switching from carrots or sweet potatoes to other vegetables could decrease the total heavy metal content on that day <a href="https://www.healthybabyfood.org/sites/healthybabyfoods.org/files/2019-10/BabyFoodReport_FULLREPORT_ENGLISH_R5b.pdf">by about 73%</a>. Root vegetables have vitamins and other nutrients, so you don’t have to abandon them altogether, but use them sparingly.</p>
<p>Making your own baby food may not reduce your child’s exposure to heavy metals. It depends on the heavy metal dosage in each of the ingredients that you are using. Organic may not automatically mean the heavy metal content is lower because soil could have been contaminated for generations before its conversion, and neighboring farm water runoff could contaminate common water sources.</p>
<h2>Is anyone doing anything about it?</h2>
<p>The <a href="https://oversight.house.gov/sites/democrats.oversight.house.gov/files/2021-02-04%20ECP%20Baby%20Food%20Staff%20Report.pdf">congressional report</a> calls for the FDA to <a href="https://www.fda.gov/food/cfsan-constituent-updates/fda-response-questions-about-levels-toxic-elements-baby-food-following-congressional-report">better define acceptable limits</a> for heavy metals in baby food. It points out that the heavy metal levels found in some baby foods far exceed the maximum levels allowed in bottled water. It also recommends standards for testing in the industry, and suggests requiring baby food makers to report heavy metals amounts on their product labels so parents can make informed choices.</p>
<p>Baby food manufacturers are also discussing the issue. The <a href="https://www.edf.org/media/baby-food-council-taking-challenge-reducing-heavy-metals-young-kids-food">Baby Food Council</a> was created in 2019 to bring together major infant and toddler food companies and advocacy and research groups with the goal of reducing heavy metals in baby food products. They created a <a href="https://foodscience.cals.cornell.edu/industry-partnership-program/cifs-ipp-councils/">Baby Food Standard and Certification Program</a> to work collaboratively on testing and certification of raw ingredients. Ultimately, baby food makers will need to consider changing farm sources of raw ingredients, using fewer seasonings and altering processing practices.</p>
<p>The U.S. has made important inroads in reducing heavy metals in air and water since the 1980s, dramatically lowering exposure. With additional focus, it can further reduce heavy metal exposure in baby food, too.</p>
<p>[<em>Understand new developments in science, health and technology, each week.</em> <a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-understand">Subscribe to The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/155443/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>C. Michael White does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Reports from baby food companies show questionable levels of arsenic, lead and other heavy metals. Here’s what parents need to know.C. Michael White, Distinguished Professor and Head of the Department of Pharmacy Practice, University of ConnecticutLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1456952020-09-15T02:33:50Z2020-09-15T02:33:50ZCOVID-19 is not the only infectious disease New Zealand wants to eliminate, and genome sequencing is a crucial tool<figure><img src="https://images.theconversation.com/files/358014/original/file-20200915-20-djs2ua.jpg?ixlib=rb-1.1.0&rect=38%2C162%2C5129%2C3269&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock/Gio.tto</span></span></figcaption></figure><p>Genome sequencing — the mapping of the genetic sequences of an organism — has helped track the spread of <a href="https://theconversation.com/genome-sequencing-tells-us-the-auckland-outbreak-is-a-single-cluster-except-for-one-case-144721">COVID-19 cases in Auckland</a>, but it also plays an important role in the control of other infectious diseases in New Zealand. </p>
<p>One example is <em>Mycoplasma bovis</em>, a <a href="https://www.biosecurity.govt.nz/protection-and-response/mycoplasma-bovis/what-is-mycoplasma-bovis/">global cattle disease</a> New Zealand also hopes to eliminate. </p>
<p>It was first detected on a South Island dairy farm in July 2017 and has subsequently been found on <a href="https://www.biosecurity.govt.nz/protection-and-response/mycoplasma-bovis/situation-report/">250 properties across the country</a>. It remains active on one farm. </p>
<p><em>M. bovis</em> causes a range of diseases in both adult cattle and calves, including pneumonia, arthritis, mastitis, conjunctivitis and middle ear infections. The original source of the incursion remains unknown, but the Ministry for Primary Industries, together with industry partners, runs a programme to <a href="https://www.scoop.co.nz/stories/PA2005/S00207/mycoplasma-boviseradication-reaches-two-year-milestone.htm">eliminate <em>M. bovis</em></a> from New Zealand. </p>
<p>Sequencing, epidemiology and evolutionary modelling all help determine how it spread between infected farms. Understanding “who infected whom” is crucial for contact tracing and control measures — and it applies whether a person is infected with COVID-19 or a cattle herd with <em>M. bovis</em>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/eradicating-cattle-disease-m-bovis-in-new-zealand-may-be-costly-even-impossible-but-we-must-try-99023">Eradicating cattle disease M. bovis in New Zealand may be costly, even impossible, but we must try</a>
</strong>
</em>
</p>
<hr>
<h2>Eliminating human and animal pathogens</h2>
<p>Several factors have contributed to the improvement in genome sequencing, including <a href="https://www.stuff.co.nz/national/health/coronavirus/300077513/coronavirus-new-research-reveals-how-covid19-came-to-new-zealand">collaboration across New Zealand</a>, an injection of <a href="https://www.otago.ac.nz/news/news/otago737458.html">new</a> <a href="https://www.hrc.govt.nz/resources/research-repository/predict-and-prevent-covid-19-data-driven-innovation-project">funding</a>, and advances in <a href="https://www.medrxiv.org/content/10.1101/2020.08.05.20168930v3">modelling</a> and <a href="https://www.rnz.co.nz/national/programmes/saturday/audio/2018739526/james-hadfield-nz-phylogeneticist-tracking-covid-19-s-spread">visualisation</a>. </p>
<figure class="align-center ">
<img alt="A map of how COVID-19 spread to Australia and New Zealand" src="https://images.theconversation.com/files/357076/original/file-20200909-18-11w33ks.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/357076/original/file-20200909-18-11w33ks.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=334&fit=crop&dpr=1 600w, https://images.theconversation.com/files/357076/original/file-20200909-18-11w33ks.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=334&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/357076/original/file-20200909-18-11w33ks.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=334&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/357076/original/file-20200909-18-11w33ks.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=419&fit=crop&dpr=1 754w, https://images.theconversation.com/files/357076/original/file-20200909-18-11w33ks.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=419&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/357076/original/file-20200909-18-11w33ks.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=419&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">This map shows how COVID-19 genome sequences track transmission routes.</span>
<span class="attribution"><a class="source" href="https://nextstrain.org/ncov/oceania?dmax=2020-04-02&dmin=2020-03-13">Nextstrain, supported by data from GISAID</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>In the case of COVID-19, the turnaround speed from test sample to viral genome sequence has increased dramatically, and the information is invaluable for New Zealand’s ongoing effort to eliminate community transmission.</p>
<p>Many disciplines and skill sets are involved in analysing genome data and linking viral or bacterial sequences with epidemiological data on specific cases. New Zealand scientists work with international colleagues at the forefront of global projects to turn genome sequencing data into information for policy and action. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-new-zealand-needs-to-focus-on-genome-sequencing-to-trace-the-source-of-its-new-covid-19-outbreak-144402">Why New Zealand needs to focus on genome sequencing to trace the source of its new COVID-19 outbreak</a>
</strong>
</em>
</p>
<hr>
<p>Apart from New Zealand’s effort to eliminate the cattle disease, other programs to control infectious diseases also benefit from genome sequencing. These include bacteria transmitted between animals and people, such as <em>Salmonella</em>, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6390770/"><em>E. coli</em></a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6874264/"><em>Campylobacter</em></a>. </p>
<p>Strategies to reduce food-borne <em>Campylobacter</em> infections in New Zealand are informed by “source attribution” models. These use bacterial sequences from human cases and animal hosts to <a href="http://www.sacnzs.org.nz/">determine the likely origin of human infection</a>. </p>
<p>This information has helped the Ministry for Primary Industries and the food industry develop and implement policy to reduce the risk of food poisoning caused by <em>Campylobacter</em>.</p>
<h2>From global to local control of infectious diseases</h2>
<p>Genome sequencing, epidemiology and evolutionary modelling have combined to help understand transmission paths of infectious diseases at different scales. In New Zealand, these include the following: </p>
<ul>
<li><p>Global transmission of <a href="https://www.sciencedirect.com/science/article/pii/S0042682219302764">influenza</a> and <a href="https://academic.oup.com/cid/article/69/3/428/5146342">severe <em>E. coli</em> infections</a> over many decades</p></li>
<li><p>transmission of <em>Salmonella</em> between <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5443446/">wildlife, livestock and people in New Zealand</a>, and between New Zealand and Australia in <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6711244/">returning travellers</a></p></li>
<li><p>identification of the source of New Zealand’s <a href="https://www.sciencedirect.com/science/article/pii/S016344532030445X">largest outbreak of a waterborne <em>Campylobacter</em> infection</a>, which affected more than 8,000 people and was caused by contamination of untreated groundwater with sheep faeces. </p></li>
</ul>
<p>In recent years, the Ministry of Health has funded the <a href="https://www.esr.cri.nz/">Institute of Environmental Science and Research</a> to routinely sequence bacteria that cause disease in people. This has supported the control of outbreaks of <a href="https://www.foodsafetynews.com/2019/05/alfalfa-sprouts-linked-to-salmonella-outbreak-in-new-zealand/#:%7E:text=Almost%2070%20people%20have%20fallen,Salmonella%20infections%20from%20alfalfa%20sprouts.&text=%E2%80%9CSalmonella%20Typhimurium%20phage%20type%20108,water%20tested%20in%20this%20outbreak."><em>Salmonella</em></a>, <em>E. coli</em>, bacterial meningitis and antibiotic-resistant bacteria. </p>
<p>New research at the <a href="https://www.nzfssrc.org.nz/research">New Zealand Food Safety Science and Research Centre</a> combines farm and factory-scale micro-mapping with genomics and modelling to control bacteria such as <em>Listeria</em> and <em>Campylobacter</em>. This helps our understanding of how microbes enter the food chain and how we can control them at the source. </p>
<h2>Genome sequencing of new epidemics</h2>
<p>We live in challenging times. We receive daily reminders of the consequences of our ability, or inability, to prevent and control emerging pathogens. Genome sequencing and modelling provide powerful opportunities to improve the management of infectious diseases globally. </p>
<p>It is exciting and encouraging to witness these advances in New Zealand. Recent investment in the country’s sequencing capability has led to an unprecedented acceleration in turnaround times. This makes the findings far more useful at the frontline of a rapidly evolving outbreak. </p>
<p>To reduce the impact of emerging diseases such as COVID-19, we need sustained investment in these new technologies. Human and animal infectious disease experts need to work together, along with experts in public health, microbiology, molecular biology, epidemiology and modelling. </p>
<p>We need to grow capability and maintain scientific networks to respond rapidly and effectively when the next disease crosses our borders.</p><img src="https://counter.theconversation.com/content/145695/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nigel French works for the New Zealand Food Safety Science and Research Centre. He receives funding from the New Zealand Food Safety Science and Research Centre and the Ministry for Primary Industries.. </span></em></p>From a global cattle disease that can devastate herds to water-borne pathogens causing severe food poisoning, genome sequencing has become an important tool in the control of infectious diseases.Nigel French, Professor of Food Safety and Veterinary Public Health, Massey UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1245952019-10-07T14:17:28Z2019-10-07T14:17:28ZRaw milk: the benefits are unclear but the dangers are real<figure><img src="https://images.theconversation.com/files/295809/original/file-20191007-121088-939mkt.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5613%2C3739&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/agriculture-industry-farming-people-animal-husbandry-558271495">Syda Productions/Shutterstock</a></span></figcaption></figure><p>According to <a href="https://www.reddit.com/r/nutrition/comments/amxtuv/consuming_raw_milk_good_or_bad/">some of</a> its <a href="https://www.mumsnet.com/Talk/am_i_being_unreasonable/3016598-Raw-milk">online proponents</a>, unpasteurised or “raw” milk can “heal the gut”, boost the immune system, prevent allergies, give you healthier skin and even contribute to bodybuilding. Perhaps more common is the idea that pasteurisation – the heating process used to kill harmful bacteria in milk – reduces the amount of vitamins and “good” bacteria in the drink, so raw milk is supposedly better for you. Recent <a href="https://www.theguardian.com/food/2019/sep/21/dairy-farmers-turn-back-clock-customers-take-fresh-look-at-milk">media reports</a> suggest this perception is creating a growing demand for raw milk that some farmers are happily responding to.</p>
<p>So what does the scientific evidence say? There’s some data to indicate pasteurisation can have a small effect on milk’s nutritional content. But drinking raw milk comes with the risk of contracting serious and potentially lethal infections.</p>
<p>Pasteurisation, named after scientist Louis Pasteur (1822-1895), <a href="https://www.dairycouncil.co.uk/consumers/industry/what-is-pasteurisation">involves heating</a> certain types of food and drink to about 72°C for a minimum of 15 seconds and then rapidly cooling them to 3°C. This process reduces the numbers of potentially harmful bacteria (pathogens) and other microorganisms that reduce the shelf life of the product.</p>
<p>A 2011 meta-analysis compared the results of <a href="https://www.ncbi.nlm.nih.gov/pubmed/22054181">40 studies</a> investigating the effects of pasteurisation on vitamin levels in milks. It showed pasteurisation did reduce the amount of vitamins B1, B2, C and folate in milk. But the authors also concluded that, apart from vitamin B2, levels of these vitamins were so low to begin with that milk wasn’t an important dietary source of them. </p>
<p>They also found some of the published scientific evidence suggested that raw milk may offer some protection from allergies. However, the numerous environmental factors involved in farming prevented any clear conclusions being made. </p>
<p>Another <a href="https://www.jacionline.org/article/S0091-6749%252814%252901274-3/abstract">study from 2015</a> looked at how often 983 babies under 12 months suffered fevers and respiratory tract infections such as colds (as recorded by their parents). It compared those who were given raw milk and those who had UHT (ultra-high temperature processed) milk, which is heated to a much higher temperature (135°C) than in regular pasteurisation.</p>
<p>The authors concluded that drinking raw milk in the first year of life could reduce the risk of fevers and respiratory infections by about 30% compared to UHT milk. They stated that if a method could be found to remove pathogens from milk with only minimal processing, then this could have an enormous impact on babies’ health, given how common these infections are.</p>
<p>But it’s important to emphasise this isn’t the same as saying raw milk has protective powers for anyone who drinks it. It’s also worth considering that babies under 12 months are usually recommended <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2791650/#targetText=Linoleic%20acid%20provides%204%25%20of,whole%20cow's%20milk%20(14).">breast milk or formula</a> because they cannot obtain all the nutrients they need from any cow’s milk. Perhaps most importantly, such young infants are at particular risk from the pathogens in raw milk, which can threaten even healthy adults. </p>
<h2>Harmful bacteria</h2>
<p>The average human body contains around <a href="https://www.nature.com/news/scientists-bust-myth-that-our-bodies-have-more-bacteria-than-human-cells-1.19136">39 trillion</a> individual bacterial cells – more than the total number of human cells in the body. We need a mixture of microorganisms, perhaps commonly known as “good” bacteria, to fight off the bad ones. </p>
<p>Since microorganisms are found everywhere from the Antarctic to the bottom of the sea, it’s perhaps unsurprising that they are commonplace on the average dairy farm. Some harmful bacteria that have been associated with raw drinking milk include <em>Mycobacterium bovis</em> (the causative agent of bovine TB), <em>Campylobacter</em>, <em>Salmonella</em>, <em>Listeria</em> and the toxin-producing <em>E. coli</em>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/295810/original/file-20191007-121088-2cabbq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/295810/original/file-20191007-121088-2cabbq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=420&fit=crop&dpr=1 600w, https://images.theconversation.com/files/295810/original/file-20191007-121088-2cabbq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=420&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/295810/original/file-20191007-121088-2cabbq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=420&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/295810/original/file-20191007-121088-2cabbq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=528&fit=crop&dpr=1 754w, https://images.theconversation.com/files/295810/original/file-20191007-121088-2cabbq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=528&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/295810/original/file-20191007-121088-2cabbq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=528&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Raw milk has been linked to food poisoning from <em>Campylobacter</em>.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/campylobacter-jejuni-bacteria-313801262?src=iEZd2cZZKFA9cJJ-c1afgg-1-4">royaltystockphoto/Shutterstock</a></span>
</figcaption>
</figure>
<p>Research has shown drinking raw milk can lead to infections with these pathogens. In Colorado, US, in 2015, 12 people were infected with a drug-resistant strain of <a href="https://www.cdc.gov/mmwr/volumes/67/wr/mm6705a2.htm"><em>Campylobacter jejuni</em></a> after drinking raw milk. Although no one died, one person was hospitalised and all had symptoms ranging from bloody diarrhoea to stomach cramps and headaches. Similarly, <a href="https://www.dairyreporter.com/Article/2017/08/15/Public-Health-Wales-investigating-Campylobacter-from-milk">in Wales</a> in 2017, 18 cases of <em>Campylobacter</em> infection were reported from people who had drunk raw milk.</p>
<p>Because of the dangers related to raw milk, its sale is often strictly regulated. For example, in most of the UK it can only be sold by <a href="https://data.gov.uk/dataset/f6706084-9c82-4a50-a781-41e0e6229948/raw-drinking-milk-premises-in-england-wales-and-northern-ireland">registered producers</a> who use approved production methods. Farms have to be inspected twice a year, and the milk has to be labelled with a health warning and tested four times a year for the presence of pathogens. But in Scotland, selling raw milk for drinking is <a href="https://www.foodstandards.gov.scot/business-and-industry/industry-specific-advice/dairy">prohibited entirely</a>, as it is in Canada and <a href="https://www.sahealth.sa.gov.au/wps/wcm/connect/3aab958041f2c9e4a7fce740535c9bd4/UCM+FAQs+-+FINAL.pdf?MOD=AJPERES&CACHEID=ROOTWORKSPACE-3aab958041f2c9e4a7fce740535c9bd4-mMHXVH2">Australia</a>.</p>
<p>The evidence for the benefits of drinking raw milk is mixed but <a href="https://www.sciencedirect.com/science/article/pii/S095671351200535X?via%253Dihub">the research</a> generally suggests that the potential contamination of raw milk with harmful bacteria is too big a risk compared to any perceived health benefits.</p><img src="https://counter.theconversation.com/content/124595/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>More people are drinking unpasteurised milk but what does the evidence say?James Blaxland, Lecturer in Microbiology, ZERO2FIVE Food Industry Centre, Cardiff Metropolitan UniversityVitti Allender, Senior Lecturer, Cardiff Metropolitan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/922562018-12-30T20:31:38Z2018-12-30T20:31:38ZHealth Check: when should you throw away leftovers?<figure><img src="https://images.theconversation.com/files/250343/original/file-20181212-110246-1ob9ss.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">If it's been out longer than four hours, it's best to throw it away.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/putting-casserole-leftovers-into-plastic-containers-511700683?src=ucRLtTrVk2eCHQtIW50Tyw-1-22">By Merrimon Crawford</a></span></figcaption></figure><p>Refrigeration is the <a href="https://royalsociety.org/news/2012/top-20-food-innovations/">most important invention</a> in the history of food. But while commercial and home refrigerators have only been used for the past 100 years or so, people have long used cool natural environments to store foods for extended periods. </p>
<p>Temperature is important for controlling microbial growth. Just as we find food wholesome, bacteria and fungi also enjoy the nutritional benefits of foods. They will consume the food and multiply, eventually “spoiling” the food (think mouldy bread or slimy lettuce). </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-to-keep-school-lunches-safe-in-the-heat-89868">How to keep school lunches safe in the heat</a>
</strong>
</em>
</p>
<hr>
<p>If the microbe can cause disease – such as <em>Salmonella</em>, <em>Campylobacter</em>, <em>E. coli</em> or <em>Listeria</em> – you’re at risk of food poisoning. Most disease-causing microbes can grow to dangerous levels even before the food is noticeably spoiled without changing the smell, taste or appearance of the food.</p>
<h2>How to stop bugs growing in our food</h2>
<p>All forms of life require a few basic things to grow: a source of energy, (sugar for us, sunlight for plants), oxygen (for higher forms of life), water and simple chemical building blocks that provide nitrogen, phosphorous and sulphur – and the correct temperature. Water is key, and denying it severely restricts microbial growth. </p>
<p>That’s why salt has long been used as a preservative for perishable foods like meats; salt binds the water and makes it unavailable to microbes. Acid can also be used (via pickling or fermentation), as most microbes don’t like acidic conditions.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/250349/original/file-20181212-110256-120h0i3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/250349/original/file-20181212-110256-120h0i3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/250349/original/file-20181212-110256-120h0i3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/250349/original/file-20181212-110256-120h0i3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/250349/original/file-20181212-110256-120h0i3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/250349/original/file-20181212-110256-120h0i3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/250349/original/file-20181212-110256-120h0i3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Don’t delay – put it in the fridge as soon as you can.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/camberley-uk-feb-1st-2017-contents-575253175?src=4FX3155Kq5VX4b8mxC7C8A-1-15">Gary Perkin/Shutterstock</a></span>
</figcaption>
</figure>
<p>Of course, cooking kills the microbes of concern, but they can contaminate and grow in the food afterwards. </p>
<p>If the food can’t be salted or pickled, or you have leftovers of cooked food, you’ll need to store the food at a temperature microbes don’t like. Refrigeration is the most effective and economical option. </p>
<p>Typically, the greater the moisture level, the more perishable the food. That’s why we can store dry foods (such as nuts) in the cupboard but high-moisture foods (such as fresh meat, vegetables) will quickly spoil if unrefrigerated.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/food-safety-are-the-sniff-test-the-five-second-rule-and-rare-burgers-safe-92661">Food safety: are the sniff test, the five-second rule and rare burgers safe?</a>
</strong>
</em>
</p>
<hr>
<h2>How to store food safely</h2>
<p>The “danger zone” is the temperature range between 5°C and 60°C, where most common food poisoning bacteria like to grow. To avoid the danger zone, keep hot foods above 60°C and store foods below 5°C. </p>
<p>The two-hour/four-hour guidelines can also help avoid food poisoning from leftovers. If perishable food has been in the danger zone for:</p>
<ul>
<li>less than two hours, use it immediately or store it appropriately</li>
<li>two to four hours, use it immediately</li>
<li>longer than four hours, discard it.</li>
</ul>
<p>So, if the food has been sitting on the table after a long lunch on a warm day, it’s probably best to discard or consume it soon afterwards. </p>
<p>If the food is OK, store it in small portions, as these will reach the right temperature sooner than larger volumes, before refrigerating or freezing. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/mondays-medical-myth-leave-leftovers-to-cool-before-refrigerating-6114">Monday's medical myth: leave leftovers to cool before refrigerating</a>
</strong>
</em>
</p>
<hr>
<p>Using some common sense, and understanding how microbes grow, can help avoid a nasty case of diarrhoea – or worse. All food business must comply with food safety standards but how we prepare, store and consume food in our homes is equally important in preventing food-borne illness.</p><img src="https://counter.theconversation.com/content/92256/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Enzo Palombo receives funding from Dairy Food Safety Victoria. </span></em></p>Did you forget to put the leftovers away? If it’s only an hour or two, that’s OK, but as the temperature drops under 60 degrees, the risk of bacterial growth – and food poisoning – increases.Enzo Palombo, Professor of Microbiology, Swinburne University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1055762018-10-31T04:46:01Z2018-10-31T04:46:01ZTrust Me, I’m An Expert: Food fraud, the centuries-old problem that won’t go away<figure><img src="https://images.theconversation.com/files/241976/original/file-20181024-48700-ywtg7v.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C3997&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What is in these products? And if additives don't affect your health, would you care?
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>What have you eaten today? And how much do you know about how it was produced, what was added to it along the way, and how it made its way to your plate?</p>
<p>Even as most of us grow increasingly removed from actual food production, many consumers still take food fraud and perceptions of food purity incredibly seriously. </p>
<p>Scandals around <a href="https://delishably.com/food-industry/Meat-Glue-What-It-Is-And-What-You-Should-Know">“meat glue”</a> or <a href="https://qz.com/1323471/ten-years-after-chinas-melamine-laced-infant-milk-tragedy-deep-distrust-remains/">milk</a> and <a href="https://www.theguardian.com/environment/2017/oct/05/honey-tests-reveal-global-contamination-by-bee-harming-pesticides">honey</a> contamination, and the skyrocketing global interest in <a href="https://www.usatoday.com/story/money/2017/07/27/organics-popularity-higher-than-ever-43-billion-2016/500129001/">organic foods</a>, underscore the fact that many of us still care quite deeply about the foods we eat and how they’re produced – and that’s affecting food labelling, regulation and consumer behaviour.</p>
<p>One person who’s studied that terrain closely is Dr Andrew Ventimiglia, a Research Fellow at The University of Queensland, who researches food fraud and how it relates to science, culture, trademark law and food regulation.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/trust-me-im-an-expert-cyclone-season-approacheth-but-this-year-theres-a-twist-104309">Trust Me, I'm An Expert: Cyclone season approacheth, but this year there's a twist</a>
</strong>
</em>
</p>
<hr>
<p>He sat down with The Conversation’s deputy politics and society editor Justin Bergman to talk about the weird history of food adulteration and certification – everything from 19th century dairy farmers adding sheep brains to skim milk to make it look frothier, to centuries-old oil and wine adulteration scandals.</p>
<p>Dr Ventimiglia said types of food fraud laws have been recorded as early as the <a href="https://www.telegraph.co.uk/news/uknews/3081008/Bread-rules-abandoned-after-750-years.html">13th century</a>, but the issue really came into focus in the <a href="http://www.artisanfoodlaw.co.uk/history-of-food-law/19th-century/history-of-food-law-19th-century">1800s</a>. </p>
<blockquote>
<p>Adulterated milk was one of the first issues that got national attention, and this was roughly in the mid 1800s to late 1800s, both particularly in the UK and the US. And the earliest form of adulterated milk that was really concerning to regulators was actually simply skim milk.</p>
<p>Producers who were making skim milk were adding flour or starch, sometimes carrots for sweetness, but they were also adding things that did pose a public health risk.</p>
<p>So, for instance, chalk was added to increase the whiteness of milk, as well as often sheep or calf brains to froth the milk […] those posed really legitimate health risks that were recognised by early analytic chemists and that really initiated some early food regulations.</p>
</blockquote>
<p>And while food scandals persist today, food standards are increasingly more concerned with fraudulent claims on packaging and innovations in food production. For instance, is yoghurt made with coconut milk still considered yoghurt? What to do about foods that claim to be “all natural?”</p>
<p>Special thanks to our multimedia intern, Dilpreet Kaur Taggar, for editing this segment together. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/trust-me-im-an-expert-how-augmented-reality-may-one-day-make-music-a-visual-interactive-experience-100318">Trust Me, I'm An Expert: How augmented reality may one day make music a visual, interactive experience</a>
</strong>
</em>
</p>
<hr>
<h2>From food adulteration to food poisoning</h2>
<p>We also hear from Associate Professor Shauna Murray from the UTS Plant Functional Biology and Climate Change Cluster, about her research into <a href="https://theconversation.com/explainer-what-is-ciguatera-fish-poisoning-21835">ciguatera fish poisoning</a>. It’s a non-bacterial illness associated with fish consumption and symptoms in humans may include gastrointestinal, neurological and even sometimes cardiovascular problems.</p>
<p>Editorial intern Jordan Fermanis spoke to Dr Murray about why this tropical disease is showing up further south, and how recreational fishermen are helping researchers unlock the mysteries of ciguatera. </p>
<hr>
<p>Trust Me, I’m An Expert is a podcast where we ask academics to surprise, delight and inform us with their research. You can download previous episodes <a href="https://theconversation.com/au/podcasts/trust-me-podcast">here</a>.</p>
<p>And please, do check out other podcasts from The Conversation – including The Conversation US’ <a href="https://theconversation.com/au/podcasts/heat-and-light-1968">Heat and Light</a>, about 1968 in the US, and <a href="https://theconversation.com/au/podcasts/the-anthill">The Anthill</a> from The Conversation UK, as well as <a href="https://theconversation.com/au/podcasts/mediafiles">Media Files</a>, a brand new podcast all about the media. You can find all our podcasts over <a href="https://theconversation.com/au/podcasts">here</a>.</p>
<h2>Additional audio and credits</h2>
<p>Additional editing by Dilpreet Kaur Taggar</p>
<p>Kindergarten by Unkle Ho, from <a href="https://www.elefanttraks.com/">Elefant Traks</a></p>
<p>Free Music Archive: Podington Bear, <a href="https://freemusicarchive.org/music/Podington_Bear/">Clouds, Rain, Sun</a></p>
<p>Demand increases for organic produce, <a href="https://www.youtube.com/watch?v=JFLAkTBXtaA">23 ABC News</a>.</p>
<p>Is your honey real honey or just “sugar syrup”? <a href="https://www.youtube.com/watch?v=gafNOtcShyI">ABC News Australia</a>. </p>
<p>Fake honey: Study finds disturbing results, <a href="https://www.youtube.com/watch?v=Z7M8R4350iw">ABC News Australia</a>.</p>
<p>Meat glue secret, <a href="https://www.youtube.com/watch?v=hXXrB3rz-xU">Today Tonight</a>. </p>
<p>Chinese milk report, <a href="https://www.youtube.com/watch?v=O-kLUyic4TM">CNN</a>. </p>
<p>Missouri Wine History, <a href="https://www.youtube.com/watch?v=MocfJiZGR_M">MissouriWine</a>.</p>
<p>Pure. Fresh. Milk. <a href="https://www.youtube.com/watch?v=7vmZOniut9Y">1991 Promo</a>. </p>
<p>Australian <a href="https://www.youtube.com/watch?v=7QphMaa4wxI">milk ad</a>. </p>
<p>Sad Marimba Planet by Lee Rosevere from <a href="http://freemusicarchive.org/music/Lee_Rosevere/Music_for_Podcasts_4/Lee_Rosevere_-_Music_for_Podcasts_4_-_02_Sad_Marimba_Planet">Free Music Archive</a></p><img src="https://counter.theconversation.com/content/105576/count.gif" alt="The Conversation" width="1" height="1" />
Dairy farmers used to put sheep brains and chalk in skim milk to make it look frothier and whiter. Coffee, honey and wine have also been past targets of food fraudsters. Can the law ever keep up?Sunanda Creagh, Senior EditorJordan Fermanis, Editorial InternJustin Bergman, International Affairs EditorDilpreet Kaur, Editorial InternLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/975712018-09-28T10:23:22Z2018-09-28T10:23:22ZChemotherapy patients are at risk from poor food safety practices at home<figure><img src="https://images.theconversation.com/files/238424/original/file-20180928-48665-y2hzvl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">More than just a stomach bug.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/weak-elderly-woman-cancer-stomach-pain-1166047576?src=wMLt622ysVvAl5KkW1U49Q-3-26">Photographee.eu/Shutterstock</a></span></figcaption></figure><p>While chemotherapy is a gruelling form of treatment in itself, the reduced immune system function that it causes can leave patients at risk from pathogens too. These illnesses can be contracted from a range of sources, including food.</p>
<p>We know that people undergoing chemotherapy are at an increased risk of <a href="https://www.sciencedirect.com/science/article/pii/0168160596009968?via%3Dihub">foodborne illness</a>. In fact, food poisoning such as <a href="https://academic.oup.com/cid/article/47/6/790/325735">campylobacteriosis</a>, <a href="https://www.sciencedirect.com/science/article/pii/S1286457907001876?via%3Dihub">listeriosis</a> and <a href="https://www.ncbi.nlm.nih.gov/books/NBK20904/">salmonellosis</a> are common among cancer patients.</p>
<p>However, <a href="https://theconversation.com/chemotherapy-patients-may-be-falling-ill-because-they-arent-aware-of-the-food-poisoning-risks-83591">our research</a> has found that chemotherapy patients may not be aware of the additional risks that foodborne bacteria present. While anyone can have food poisoning, those who are undergoing chemotherapy treatment can be made seriously ill simply because the food they are eating isn’t being handled properly. Foodborne infections can cause delays in treatment and potentially increase patient mortality.</p>
<p>To reduce the chance of contracting a foodborne infection it is essential that patients and those caring for them adhere to <a href="http://www.who.int/foodsafety/publications/consumer/en/5keys_en.pdf?ua=1">key food safety practices</a>. As well as sticking to use-by dates, these practices include cleaning hands, surfaces and equipment, cooking foods thoroughly, separating ready-to-eat food from raw food and <a href="https://theconversation.com/your-fridge-might-not-be-cold-enough-to-keep-food-safe-70262">keeping food at safe refrigeration temperatures</a>.</p>
<h2>Keeping patients safe</h2>
<p><a href="https://www.publichealthjrnl.com/article/S0033-3506(17)30220-2/fulltext?code=puhe-site">Our previous research</a> looked specifically at the food safety information which is available to people receiving chemotherapy treatment from NHS hospitals. We found that a clear lack of consistent, correct and credible information on the critical importance of food safety for chemotherapy patients. Exploring the issue further, we have been assessing what people receiving treatment and their families know about food safety and how they implement this knowledge at home. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/229577/original/file-20180727-106502-1afikd3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/229577/original/file-20180727-106502-1afikd3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/229577/original/file-20180727-106502-1afikd3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=850&fit=crop&dpr=1 600w, https://images.theconversation.com/files/229577/original/file-20180727-106502-1afikd3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=850&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/229577/original/file-20180727-106502-1afikd3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=850&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/229577/original/file-20180727-106502-1afikd3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1068&fit=crop&dpr=1 754w, https://images.theconversation.com/files/229577/original/file-20180727-106502-1afikd3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1068&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/229577/original/file-20180727-106502-1afikd3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1068&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">WHO advice on keeping food safe.</span>
<span class="attribution"><span class="source">World Health Organization</span></span>
</figcaption>
</figure>
<p>As described in our <a href="https://onf.ons.org/onf/45/5/food-safety-knowledge-and-self-reported-food-handling-practices-cancer-treatment">recently published research</a>, we found that although people receiving chemotherapy and their families are aware of some food safety practices relating to refrigeration, cooking and cleaning, they are still following potentially unsafe practices when handling and storing food at home.</p>
<p>The study involved 172 people, most of whom had received chemotherapy for treatment of cancer in the past three years. 51 of this number were family members, who had been responsible for preparing food for partners or children during chemotherapy. We found that less than half of the people surveyed had received any information about food safety from healthcare providers. People with neutropenia (an abnormally low level of white blood cells, which fight infections), blood-related cancers, or those that had received a transplant were significantly more likely of receiving information on food safety. We presume this is because they are at an increased risk of infection, but haven’t conducted research with healthcare providers on this point specifically.</p>
<h2>Unsafe practices</h2>
<p>Although those that said they had received information were found to be more knowledgeable about food safety, gaps in their awareness and potential food safety malpractices were still reported. In particular, we found that awareness of when to wash hands was very high and hand-washing practices were frequently reported to be implemented in the home. But the reported hand-washing methods were inadequate. Only 58% reportedly rubbed their hands together and between fingers with soap for the recommended 20 seconds when washing.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/225494/original/file-20180629-117425-jz64m3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225494/original/file-20180629-117425-jz64m3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/225494/original/file-20180629-117425-jz64m3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=842&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225494/original/file-20180629-117425-jz64m3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=842&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225494/original/file-20180629-117425-jz64m3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=842&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225494/original/file-20180629-117425-jz64m3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1058&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225494/original/file-20180629-117425-jz64m3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1058&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225494/original/file-20180629-117425-jz64m3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1058&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">How to wash your hands properly.</span>
<span class="attribution"><span class="source">ZERO2FIVE Food Industry Centre</span></span>
</figcaption>
</figure>
<p>Most participants also knew of the importance of ensuring fridges were kept at the right temperature (<a href="https://theconversation.com/your-fridge-might-not-be-cold-enough-to-keep-food-safe-70262">below 5°C</a>) but only 35% said that they used a thermometer to check their own fridge was correct. Similarly, with cooking, although the chemotherapy patients and family members knew to ensure food was cooked thoroughly, 78% said they never used a meat thermometer to make sure it was done.</p>
<p>We also found a particular issue in relation to raw poultry. Many participants thought that they needed to wash raw poultry (and did so). But washing poultry is a food safety malpractice. Water splashes created when washing raw meat can result in the transfer of pathogens and cause <a href="https://www.campdenbri.co.uk/_access/download.php?type=research&file=1257.pdf&access=public&name=CampdenBRI-RD170.pdf&hash=70b0caed9de6eee1c68379e81bf29e4f247ef9c61d75b1b7a856e9965f4ea2e5">cross-contamination in the kitchen</a>.</p>
<p>Looking to prepackaged foods, we found that up to 40% relied upon, taste, smell or the look of food, rather than following use-by dates. Although food might appear ok, use-by dates are the only reliable way to ensure food safety. These dates are determined by looking at bacteria growth to ensure that dangerous levels are not exceeded between when the product is made and consumed.</p>
<p>We are now looking at how healthcare providers can deliver credible and effective food safety information to those receiving chemotherapy and their families. But what we can tell from our research to date is that people receiving chemotherapy need to be made aware just how critical food safety can be to their health.</p><img src="https://counter.theconversation.com/content/97571/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Ellen W. Evans received funding from Tenovus Cancer Care to facilitate this study. She is affiliated with the International Association for Food Protection.
This article refers to research co-authored with Dr Elizabeth C. Redmond.</span></em></p>Patients undergoing chemotherapy are at particular risk from food poisoning - but they aren’t being made aware how critical food safety is at home.Ellen W. Evans, Junior Research Fellow, Cardiff Metropolitan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/981522018-06-14T05:58:51Z2018-06-14T05:58:51ZResearch Check: can tea towels cause food poisoning?<figure><img src="https://images.theconversation.com/files/223142/original/file-20180614-32313-n2bp35.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Let your tea towel dry out after each use to reduce its bacterial load.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/profile-view-young-couple-washing-drying-295734776?src=SoUw9BDl2nbZNp2E-luduQ-1-5">Shutterstock/antoniodiaz</a></span></figcaption></figure><p>Aside from being up to the task of drying our dishes, we don’t usually give the humble tea towel much thought. But this week it’s being blamed for causing food poisoning: </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1005589963403091968"}"></div></p>
<p>But there’s no cause for concern.</p>
<p>Yes, bacteria can accumulate on tea towels, especially when they’re infrequently washed and don’t dry out between use. But most of the bacteria the researchers found on tea towels are not responsible for food poisoning or other gastrointestinal symptoms.</p>
<p>While the media reports focused on the food poisoning risk, the research didn’t actually look at the participants’ gastrointestinal health. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-what-is-gastroenteritis-and-why-cant-i-get-rid-of-it-34351">Explainer: what is gastroenteritis and why can't I get rid of it?</a>
</strong>
</em>
</p>
<hr>
<h2>How was the research conducted?</h2>
<p>The story came about from a <a href="http://www.abstractsonline.com/pp8/#!/4623/presentation/15470">June 9 poster presentation</a> to the American Society of Microbiology’s 2018 meeting in Atlanta, based on research carried out at the University of Mauritius. </p>
<p>The Mauritian researchers purchased <a href="https://www.medpagetoday.com/meetingcoverage/asmmicrobe/73401">100 tea towels</a> to give to the study participants; 36 were a mixture of cotton and nylon, 33 were pure nylon, and 31 were pure cotton. </p>
<p>After one month of use, the towels were collected to “culture” any bacteria present on them. This means taking bacterial samples and letting them grow in a petri dish to determine the type of organism. </p>
<p>The participants also completed a questionnaire about their tea towel use, diet and family size. </p>
<p>The research did not look at whether the participants had food poisoning or other gastrointestinal illnesses. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/food-safety-are-the-sniff-test-the-five-second-rule-and-rare-burgers-safe-92661">Food safety: are the sniff test, the five-second rule and rare burgers safe?</a>
</strong>
</em>
</p>
<hr>
<h2>What were the results?</h2>
<p>Bacterial growth was found in 49% of the kitchen towels. Cotton towels had higher levels of bacteria than nylon towels or a mixture of the two. </p>
<p>Bacterial growth increased significantly with increased family size and the presence of children. </p>
<p>Tea towels which were considered “multipurpose” – such as for cleaning table and bench tops in addition to the kitchen – had higher levels of bacteria than towels that were “single purpose”, such as drying hands and dishes in the kitchen.</p>
<p>The researchers found “humid” (or moist) towels had significantly greater concentrations of certain types of bacteria, such as coliforms. <a href="https://www.health.ny.gov/environmental/water/drinking/coliform_bacteria.htm">Coliforms</a> are a broad class of bacteria found in the digestive tract of animals including humans, and are found in their faeces. Although most coliforms are harmless, some rare strains can cause serious illness. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/223143/original/file-20180614-32307-gwa5n9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/223143/original/file-20180614-32307-gwa5n9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/223143/original/file-20180614-32307-gwa5n9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/223143/original/file-20180614-32307-gwa5n9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/223143/original/file-20180614-32307-gwa5n9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/223143/original/file-20180614-32307-gwa5n9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/223143/original/file-20180614-32307-gwa5n9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Washing your tea towel after each use is ideal but often not practical.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/tea-towels-on-washing-line-blowing-2273449?src=MGp9rFsLGUgTnC3CsNB_7Q-1-79">Sean Nel/Shutterstock</a></span>
</figcaption>
</figure>
<p>They also found that <a href="https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/staphylococcus-aureus-golden-staph">Staphylococcus aureus</a> (S. aureus), a common baterium that lives on the skin, was isolated at a significantly higher rate from families of lower socioeconomic status and families with children, as well as bigger families. </p>
<p>They looked at the influence of diet. Coliform and S. aureus were detected on tea towels at a significantly higher rate from families on non-vegetarian diets.</p>
<p>A higher prevalence of enterococcus species was detected on the kitchen towels of vegetarian families. <a href="http://www.stjames.ie/Patients/Infectionpreventioncontrol/VRE.pdf">Enterococci</a> are bacteria which are normally found in a person’s gastrointestinal tract and do not normally cause infections in healthy people, but may in those with a weakened immune system. </p>
<h2>What does it all mean?</h2>
<p>The research is interesting but shouldn’t cause concern. The majority of bacteria identified were enterococcus and pseudomonas species which are not classically involved with <a href="http://www.foodstandards.gov.au/consumer/safety/foodpoison/Pages/default.aspx">food poisoning</a> unlike campylobacter, salmonella, escherichia and listeria species. </p>
<p>But there are some practical points to take away from the research.</p>
<p>For the best protection, <a href="https://www.food.gov.uk/sites/default/files/media/document/cloths.pdf">wash the tea towel after every use</a>. But most of us are unlikely to do this, so waiting until tea towels are dry is okay, as drier tea towels will have a lower bacteria load. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/whats-the-most-hygienic-way-to-dry-your-hands-54196">What's the most hygienic way to dry your hands?</a>
</strong>
</em>
</p>
<hr>
<p>It’s best to use tea towels for a single purpose such as drying the dishes, rather than multiple purposes. This will reduce the towel’s bacterial load. </p>
<p>Disposable paper towels are less likely to accumulate bacteria than tea towels that are used multiple times, but the research is yet to establish whether they lessen the risk of gastroenteritis.</p>
<p>Surprisingly, tea towels are not the dirtiest item in the kitchen. <a href="http://www.nsf.org/consumer-resources/studies-surveys-infographics/germ-studies/germiest-items-home">More than 75% of dish sponges/rags</a> contain bacteria. Yet most people who use dish sponges/rags with their hands don’t get gastroenteritis. </p>
<h2>What else do we need to take into account?</h2>
<p>What we don’t know in this research is what the participants were using for kitchen cleaning before being given the tea towels. Were they using tea towels, a rag or disposable wipes? </p>
<p>We also don’t know how frequently participants cleaned their assigned tea towels and what they used to clean them.</p>
<p>The bacterial growth was found to increase significantly with increased family size, extended family and the presence of children. But does that mean the family members and/or children were using the tea towels more or could it be due to other factors such as children playing outdoors in a dirty environment and bringing organisms back to the house? That was not addressed in the poster.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/223144/original/file-20180614-32310-s13a83.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/223144/original/file-20180614-32310-s13a83.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/223144/original/file-20180614-32310-s13a83.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/223144/original/file-20180614-32310-s13a83.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/223144/original/file-20180614-32310-s13a83.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/223144/original/file-20180614-32310-s13a83.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/223144/original/file-20180614-32310-s13a83.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">It’s best to use a different cloth to wipe down benches.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/RjZjYwimO6Y">Nick Karvounis</a></span>
</figcaption>
</figure>
<p>Generalising the findings to different countries may be a problem. Mauritius is a <a href="https://en.wikipedia.org/wiki/Mauritius">tropical country</a> and the type and quantity of bacteria on tea towels there could very well be different than in a country with a colder, temperate climate.</p>
<p>Finally, this research was a poster presentation at the American Society of Microbiology meeting this year. The process of getting research published in a peer reviewed journal is a more intense and exhaustive process, which helps to iron out any flaws in the methodology or findings that may not be obvious to the investigators at the time. </p>
<p>So it’s helpful to wait for the formal publication which will have gone through the peer review process before we can extrapolate more conclusions. – <strong>Vincent Ho</strong></p>
<hr>
<h2>Blind peer review</h2>
<p>This Research Check accurately reflects the abstract. This study is <a href="https://blogs.jwatch.org/hiv-id-observations/index.php/news-flash-world-isnt-sterile/2018/04/01/">one of many</a> that look at bacterial contamination of household items, without reference to more relevant outcomes such as illness rates.
– <strong>Allen Cheng</strong></p><img src="https://counter.theconversation.com/content/98152/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Allen Cheng receives funding from the Australian National Health and Medical Research Council.</span></em></p><p class="fine-print"><em><span>Vincent Ho does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Yes, bacteria can accumulate on tea towels. But most of the bacteria the researchers found are not responsible for food poisoning or other gastrointestinal symptoms.Vincent Ho, Senior Lecturer and clinical academic gastroenterologist, Western Sydney UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/951952018-04-27T10:35:33Z2018-04-27T10:35:33ZHow virtual reality training could reduce your chance of food poisoning<figure><img src="https://images.theconversation.com/files/216626/original/file-20180427-95636-6rabtm.jpg?ixlib=rb-1.1.0&rect=0%2C1100%2C5613%2C2554&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Food hygiene and virtual reality could go hand in hand</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:-rpTEN_-_Tag_2_(26723765401).jpg#filelinks">rp10</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p><a href="http://www.who.int/en/news-room/fact-sheets/detail/food-safety">According to the WTO</a>, 600m people each year suffer illnesses after eating contaminated food. It is an issue which has massive consequences, not only for public health but also for national economies. And unfortunately, <a href="https://www.foodmanufacture.co.uk/Article/2014/06/30/Food-poisoning-cases-in-the-UK-exceed-1M">incidents of food-borne illnesses are increasing</a>.</p>
<p>One way of tackling this is by improving food hygiene training. Alongside <a href="http://blogs.nottingham.ac.uk/digitalresearch/category/digital-research-case-studies/the-corrupt-kitchen-case-study/">a group of interdisciplinary academics</a>, I’m creating a <a href="https://www.youtube.com/watch?v=FIsF10h-CIc&t=23s">virtual reality experience</a> that will help train individuals in kitchen hygiene. With technology rapidly developing, virtual reality (VR) experiences are increasing in complexity and utility. Cheaper and more easily portable VR headsets, when combined with <a href="https://www.youtube.com/watch?v=acktp-Wy8Nw">physical spaces that mirror</a> your virtual experience, hold huge potential <a href="https://disruptionhub.com/training-useful-application-vr/">to alter</a> how training is delivered.</p>
<p>Using simulations for safe training purposes has been used in some fields for many years. In the 1950s, simulations formed a <a href="https://books.google.co.uk/books?id=AeADAAAAMBAJ&pg=PA87&dq=1954+Popular+Mechanics+January&hl=en&sa=X&ei=CFMiT_23OIGvgwf68vjqCA&redir_esc=y#v=onepage&q&f=true">central part of pilot training</a>. But since then, the technology that underpins simulations has improved. While it has been used to provide safety training for those working in particularly dangerous environments, such as <a href="https://www.offshore-technology.com/features/virtual-reality-training/">offshore rigs</a> and <a href="https://link.springer.com/chapter/10.1007/978-3-319-58750-9_77">mines</a>, it has the potential to be equally important for less hazardous jobs. Indeed, the US Postal Service recently began <a href="https://www.trucks.com/2017/08/24/virtual-reality-truck-driver-training/">using virtual reality to train lorry drivers</a> and found that it reduced road traffic accidents involving USPS employees by 7%.</p>
<h2>Safety and hygiene</h2>
<p>Food safety and hygiene are hugely important for both the public and the economy. Contaminated foods are responsible for a high number of severe illnesses and even deaths. In 2011, an <a href="http://www.efsa.europa.eu/en/press/news/120711"><em>E. Coli</em> 0104 outbreak</a> killed at least 53 people in the EU. Economically, food safety is hugely important also. In order for consumers to be confident in buying food they need to have confidence in its safety. Unfortunately, incidence of food-borne illness appears to be increasing rather than decreasing <a href="https://www.ncbi.nlm.nih.gov/pubmed/20500787">across the world</a>. This may partially be due to a lack of hygienic practices <a href="https://www.sciencedirect.com/science/article/pii/S0956713517302633">in the food supply chain</a>. So, the proper training of business owners and staff is one of the most important means for tackling the spread of potentially devastating illnesses. </p>
<p>In our virtual reality training, the user acts as a chef with an endless queue of customers. She must prepare the food and ensure it is safe to eat. At the same time, she is being tested on whether she remembers to wash her hands or mop the floor. When rats begin to infest the kitchen, the user must decide upon the best course of action. If she fails to prepare the food in a safe or hygienic manner, she watches the customers become ill in front of her. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/216508/original/file-20180426-175074-ia1azd.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/216508/original/file-20180426-175074-ia1azd.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216508/original/file-20180426-175074-ia1azd.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216508/original/file-20180426-175074-ia1azd.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216508/original/file-20180426-175074-ia1azd.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216508/original/file-20180426-175074-ia1azd.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216508/original/file-20180426-175074-ia1azd.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The virtual reality experience forces users to respond to rat infections.</span>
<span class="attribution"><a class="source" href="http://blogs.nottingham.ac.uk/digitalresearch/category/digital-research-case-studies/the-corrupt-kitchen-case-study/">Paul Tennant</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Of course, food hygiene training is not always the highlight of employment. But we’ve found that VR helps engage the trainee, immersing them in the experience. By giving trainees the opportunity to practice their knowledge and see the consequences of their actions, we provide them with a deep learning experience. And this is where VR training excels beyond your usual real-life training exercises. </p>
<p>With VR, users can practice in a safe environment where they are able to make mistakes and learn from them. If the experience is recorded, users and trainers can revisit the user’s actions, which is invaluable for providing tailored feedback. Importantly for employers, as large numbers of users can train in parallel, VR can also help overcome tight kitchen space limitations.</p>
<h2>Ups and downs</h2>
<p>But there are also downsides to using VR . For a start, you have to train people to use the technology in the first place. Building a tutorial that enables users to become comfortable with the technology is incredibly important, particularly where the users may be diverse in terms of experience. Another unfortunate problem is that being inside a simulation can be disorienting and even give rise to motion sickness. </p>
<p>That being said, virtual reality has the potential to be a valuable tool for safety training. As the USPS programme has demonstrated, it can tangibly increase safety, but also has the potential to engage employees in a more creative way. </p>
<p>For food service employees, virtual reality has the potential to provide disruptive, immersive and stimulating training experiences, which both allow knowledge to be put into practice and enable trainees to appreciate the consequences of their actions. This will hopefully have a greater impact on their hygiene practices, and ultimately improve the safety of food for consumers.</p><img src="https://counter.theconversation.com/content/95195/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Hyde does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>As incidents of food-borne illnesses increase, virtual reality could help better train food hygieneRichard Hyde, Assistant Professor in Law, Faculty of Social Sciences, University of NottinghamLicensed as Creative Commons – attribution, no derivatives.