tag:theconversation.com,2011:/nz/topics/bacterial-diseases-49700/articlesBacterial diseases – The Conversation2022-11-15T16:03:22Ztag:theconversation.com,2011:article/1943842022-11-15T16:03:22Z2022-11-15T16:03:22ZScarlet fever outbreak in Scotland: what you need to know<figure><img src="https://images.theconversation.com/files/495058/original/file-20221114-25-ybcbgu.jpg?ixlib=rb-1.1.0&rect=35%2C14%2C4709%2C3144&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/tongue-child-scarlet-fever-strawberry-1553591399?showDrawerOnLoad=true">Lukassek/Shutterstock</a></span></figcaption></figure><p>Cases of scarlet fever in Scotland are “<a href="http://www.nhsborders.scot.nhs.uk/patients-and-visitors/latest-news/2022/november/7/scarlet-fever-in-the-community/">unseasonably high</a>”, according to NHS Borders Health Protection team.</p>
<p>Parents are being asked to be vigilant for symptoms and to seek treatment if they suspect their child has the disease. Because of the highly infectious nature of scarlet fever, those affected are being advised to stay at home <a href="http://www.nhsborders.scot.nhs.uk/patients-and-visitors/latest-news/2022/november/7/scarlet-fever-in-the-community/">for at least 24 hours</a> after beginning antibiotics.</p>
<p>Scarlet fever is a seasonal illness, with cases typically appearing in spring. However, during the first two years of the COVID pandemic, <a href="https://www.gov.uk/government/publications/group-a-streptococcal-infections-activity-during-the-2021-to-2022-season/group-a-streptococcal-infections-update-on-seasonal-activity-in-england-2021-to-2022#:%7E:text=Notifications%20and%20GP%20consultations%20of,for%20this%20time%20of%20year.">cases dropped</a> significantly, probably due to social distancing, isolation and increased handwashing. </p>
<p>But since the UK dropped these COVID measures, there has been an increase in scarlet fever cases (and other infectious diseases) outside of the usual seasonal occurrences. This is something that is happening globally. It is called the “<a href="https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(22)00544-8/fulltext">immunity debt</a>”.</p>
<p>Scarlet fever is caused by streptococcus bacteria. Symptoms typically begin with a sore throat and fever, followed by a telltale red rash on the body and tongue, called “strawberry tongue”.</p>
<p>The bacteria responsible for scarlet fever lives in the nose and throat, and those infected can spread the disease by coughing, talking or sneezing. The bacteria can also spread from touch contact with streptococcal skin infections, such as impetigo.</p>
<figure class="align-center ">
<img alt="Streptococcus pyogenes bacteria" src="https://images.theconversation.com/files/495065/original/file-20221114-12-cx1kb7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/495065/original/file-20221114-12-cx1kb7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/495065/original/file-20221114-12-cx1kb7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/495065/original/file-20221114-12-cx1kb7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/495065/original/file-20221114-12-cx1kb7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/495065/original/file-20221114-12-cx1kb7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/495065/original/file-20221114-12-cx1kb7.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">
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<span class="caption">Gram-positive bacteria Streptococcus pyogenes that cause scarlet fever.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/grampositive-bacteria-streptococcus-pyogenes-which-cause-668814304">Kateryna Kon/Shutterstock</a></span>
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<p>The disease is most common in children aged between the ages of two and eight years old, with schools and daycare centres being typical sources of exposure. A child with scarlet fever may be uncomfortable for a short time, but with antibiotics, paracetamol and rest they should recover within five days. But this wasn’t always the case.</p>
<h2>The path to a cure</h2>
<p>Historically, scarlet fever was not a short-term inconvenience to parents and children, but a far more fearful and deadly disease. Between 1900 and 1910 <a href="https://books.google.com.au/books?id=iMnN4fZrj70C&pg=PA48&redir_esc=y#v=onepage&q&f=false">36,000</a> died of scarlet fever in England and Wales alone. Famously, Charles Darwin’s infant son succumbed to scarlet fever. Of all those who died of scarlet fever, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2271647/">95%</a> were under ten years of age.</p>
<p>In the 1800s, treatments relied on managing the fever and ensuring the child rested. A research paper from 1835 describes doctors using <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5781081/">bloodletting</a> to treat scarlet fever. This involved the withdrawal of blood to “cure” infection.</p>
<p>As of the early 1900s, houses infected with scarlet fever would typically have a brightly coloured quarantine sign placed outside to isolate infected people and prevent the further spread of this disease.</p>
<p>It wasn’t until 1924 that husband and wife bacteriologist team, <a href="https://jamanetwork.com/journals/jama/article-abstract/238085">George and Gladys Dick</a>, first identified that the bacteria responsible for “strep throat” released a toxin in the body causing scarlet fever.</p>
<p>Scarlet fever remained an important infectious disease until the introduction of antibiotics in the 1940s. Following Alexander Fleming’s identification of penicillin in 1928, researchers at Oxford University worked to create a pharmaceutical version of penicillin, and in 1941, penicillin was used to treat a streptococcal infection.</p>
<p>Today, penicillin is easily available with a written prescription from a GP in the UK, and a short course of penicillin is effective for treating any new cases of scarlet fever.</p>
<figure class="align-center ">
<img alt="A child's face showing a scarlet fever rash." src="https://images.theconversation.com/files/495128/original/file-20221114-22-pm3sk5.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/495128/original/file-20221114-22-pm3sk5.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=346&fit=crop&dpr=1 600w, https://images.theconversation.com/files/495128/original/file-20221114-22-pm3sk5.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=346&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/495128/original/file-20221114-22-pm3sk5.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=346&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/495128/original/file-20221114-22-pm3sk5.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=435&fit=crop&dpr=1 754w, https://images.theconversation.com/files/495128/original/file-20221114-22-pm3sk5.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=435&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/495128/original/file-20221114-22-pm3sk5.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=435&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A typical scarlet fever rash.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/w/index.php?curid=10714448">Estreya/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
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<h2>Outbreaks still occur</h2>
<p>There have been many outbreaks of the disease in the UK in recent decades. Outbreaks were <a href="https://www.sciencedirect.com/science/article/abs/pii/S147330991730693X">particularly high in 2014</a> in Yorkshire and the East Midlands, but with penicillin and isolation, they were soon brought under control.</p>
<p>Although we can easily treat scarlet fever, we must still ensure we react to outbreaks with a degree of seriousness. The misuse of antibiotics over previous decades has led to several strains of bacteria becoming <a href="https://www.who.int/news-room/fact-sheets/detail/antibiotic-resistance">resistant to the antibiotics</a>. Previously treatable diseases, such as tuberculosis, are now becoming extremely difficult to treat.</p>
<p>If your child, following a sore throat, develops a red rash with a similar texture to sandpaper, contact your GP. If your child receives a diagnosis of scarlet fever, isolate at home with your child for at least 24 hours after starting antibiotics. And notify your child’s school or daycare centre of the diagnosis.</p>
<p>During periods of outbreaks, ensure children are washing their hands often, don’t allow them to share cups with other children, and dispose of used tissues in a bin.</p>
<p>With responsible action, we can control outbreaks and reduce the likelihood of us one day experiencing a penicillin-resistant strain of the scarlet fever bacteria.</p><img src="https://counter.theconversation.com/content/194384/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emily Johnston 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>Cases of scarlet fever have bounced back with a vengeance now that COVID measures have been lifted.Emily Johnston, Lecturer, Public Health, Sheffield Hallam UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1607162021-06-06T09:00:03Z2021-06-06T09:00:03ZHow The Gambia beat trachoma, an infection that causes blindness<figure><img src="https://images.theconversation.com/files/402320/original/file-20210524-21-1tzhvoe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A health worker examines a child for signs of trachoma </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/an-african-ministry-of-health-worker-with-opthamology-news-photo/72546415?adppopup=true">Joe McNally/Getty Images </a></span></figcaption></figure><p>The government of <a href="https://www.britannica.com/place/The-Gambia">The Gambia</a> recently <a href="https://www.iapb.org/news/the-gambia-eliminates-trachoma-as-a-public-health-problem/">announced</a> that the country had eliminated trachoma, a highly contagious eye disease, after years of hard work by health workers, nongovernmental organisations (NGOs) and communities. </p>
<p>In The Gambia, the disease <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1041660/">accounted</a> for 17% of the reported blindness in a national survey in 1986. The prevalence of trachoma has dropped from <a href="https://pubmed.ncbi.nlm.nih.gov/9828780/">0.1% to 0.02%</a> in the last 10 years. Current <a href="https://www.iapb.org/news/the-gambia-eliminates-trachoma-as-a-public-health-problem/">estimates</a> show a prevalence of less than 0.2% in adults aged over 15 years. This is about one case per 1,000 people.</p>
<p>Trachoma has been <a href="https://academic.oup.com/bmb/article/84/1/99/382442">described</a> as the most infectious cause of blindness in the world, <a href="https://www.who.int/news-room/fact-sheets/detail/trachoma">responsible for 1.4%</a> of blindness. It is <a href="https://idpjournal.biomedcentral.com/articles/10.1186/s40249-020-0630-9">one</a> of the 20 neglected tropical diseases that plague over a billion of the world’s poorest people. </p>
<p>As at <a href="https://www.who.int/news-room/fact-sheets/detail/trachoma">September 2020</a>, 13 countries had reported that they had eliminated it as a disease of public health concern. Others in Africa were Ghana and Morocco. Togo is <a href="https://endinafrica.org/news/its-time-to-take-togo-off-the-who-trachoma-list/">pending</a> validation from the World Health Organisation. The organisation has <a href="https://www.who.int/news-room/fact-sheets/detail/trachoma">validated</a> the claims of 10 of the 13 countries. </p>
<p>The WHO lists <a href="https://www.who.int/trachoma/resources/who_htm_ntd_2016.8/en/#:%7E:text=In%202012%2C%20Oman%20became%20the,as%20a%20%E2%80%9Cverification%E2%80%9D%20exercise.&text=The%20process%20for%20diseases%20targeted,been%20defined%20as%20%E2%80%9Cvalidation%E2%80%9D">strict guidelines</a> to determine whether trachoma has in fact been eliminated from endemic countries. One is that there must be a system in place to identify and, where necessary, manage any new cases in line with protocols. This means that once a country is confirmed as having eliminated trachoma, a resurgence is not expected. </p>
<p>As we are involved in the ongoing <a href="https://espen.afro.who.int/system/files/content/resources/NIGERIA_NTD_Master_Plan_2015_2020.pdf">Nigerian effort</a> to curb trachoma, my colleagues and I are studying countries like The Gambia closely for guidance.</p>
<p>Sario Kanyi, the coordinator of The Gambia’s trachoma elimination initiative, <a href="https://ehp.niehs.nih.gov/doi/10.1289/EHP2699">said</a> its success started in the community. He added that once people knew what trachoma was, they took charge and helped in communicating what had to be done.</p>
<h2>What is trachoma?</h2>
<p>Trachoma is an infection caused by the bacteria <em>Chlamydia trachomatis</em>. It can be spread through physical contact with the eyes, nose or throat of those infected. It can also be picked up from the items used by infected individuals, such as face towels.</p>
<p>Crowded conditions and poor sanitation have been identified as possible enabling factors. </p>
<p>The signs and symptoms of trachoma include: mild itching and irritation of the eyes and eyelids, a discharge of mucus and pus, eyelid swelling and sensitivity to light. </p>
<p>Others are ocular pain, redness of the eye and vision loss. Young children are the <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0009067">most susceptible</a> to trachoma infection. It usually progresses slowly, presenting with more painful symptoms at adulthood.</p>
<p>Repeated episodes of active trachoma can cause the eyelid to be scarred. In some individuals this leads to trachomatous trichiasis, in which the eyelashes turn inward and touch the eye, causing extreme pain. If left untreated it can lead to blindness. </p>
<p>Treating trachoma requires a strategy that integrates four steps known as <a href="https://www.trachomacoalition.org/prevention-and-treatment-strategy">“SAFE”</a>. The letters stand for surgery (to alleviate eye pain or prevent further complications), antibiotics, facial cleanliness and environmental sanitation.</p>
<h2>The Gambian success story</h2>
<p>The Gambia <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1041660/">established</a> an eye care programme in 1986. It also initiated policies that helped in combating the condition. </p>
<p>The country mobilised resources through partnerships with local and international specialists, such as the London School of Hygiene and Tropical Medicine.</p>
<p>A trachoma task force was created under the Gambian National Eye Programme. This was helped by the small size of the country’s population, <a href="https://www.worldometers.info/world-population/gambia-population/#:%7E:text=Gambia%202020%20population%20is%20estimated,(and%20dependencies)%20by%20population">2.4 million</a>, which allowed intervention to easily reach most citizens.</p>
<p>Clinical staff were trained and retrained to deliver surgical procedures to manage the disease. Lid surgeries were then carried out to correct turning in of scarred eyelids and damage to the cornea.</p>
<p>The Gambia undertook campaigns to educate the public on the risks posed by the disease, and about preventive measures like hygiene. Open defecation and proper face and hand hygiene were addressed by building latrines and boreholes for communities.</p>
<p>It also created a network of eye care units across the country with the sole aim of diagnosing and treating people with trachoma. High potency antibiotics were also mass administered to reduce the average bacterial load in the endemic areas of The Gambia.</p>
<p>Thousands of community health volunteers were trained to go from house to house to find people with the disease. The government had support from several NGOs. The Gambia also adhered to the World Health Organisation’s <a href="https://www.trachomacoalition.org/prevention-and-treatment-strategy">SAFE strategy</a> for eliminating trachoma. </p>
<p>A major component of the SAFE strategy is the mass distribution and administration of Azithromycin. This antibiotic was donated by Pfizer to national programmes that are implementing the trachoma strategy in The Gambia. This led to monitoring of the bacteria load in a community before and after treatment. </p>
<p>Recent <a href="https://www.nature.com/articles/s41598-017-15056-7#Sec6">studies</a> have been done in The Gambia on measuring the rate of reinfection after mass treatment programmes. The <a href="https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0004906">experts do not</a> foresee a reemergence of trachoma in the country even with the risk of infected individuals coming from Senegal to Gambia, where disease is endemic.</p>
<p>The Gambia’s success in eliminating trachoma prevents the occurrence of about <a href="https://pubmed.ncbi.nlm.nih.gov/9828780/">100,000</a> new cases, saving people pain and possible blindness. It also means that resources previously allocated to combating the disease can now be reallocated to other public health conditions.</p><img src="https://counter.theconversation.com/content/160716/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>The Gambia’s success in eliminating trachoma means that resources previously allocated to combating the disease can now be reallocated to other public health conditionsMusa Mutali, Lecturer of Optometry, University of BeninLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1389422020-06-05T10:14:06Z2020-06-05T10:14:06ZWe’ve discovered how these deadly bacteria use a common sugar to spread through the body. It could help us stop them<figure><img src="https://images.theconversation.com/files/339967/original/file-20200605-176595-nbrexv.jpg?ixlib=rb-1.1.0&rect=9%2C9%2C3285%2C2534&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://phil.cdc.gov/Details.aspx?pid=23253">CDC/Antibiotic Resistance Coordination and Strategy Unit. Medical Illustrator: Meredith Newlove</a></span></figcaption></figure><p>Although bacteria are single-celled and microscopically small, they still need energy to survive, just like us. One of the most efficient ways of acquiring energy for bacteria is through sweet, soluble carbohydrates: sugars. </p>
<p>In fact, the keen ability of the deadly bacteria <em>Streptococcus pneumoniae</em> to use the plant-derived sugar <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/raffinose">raffinose</a> may explain how it <a href="https://www.nature.com/articles/s41579-018-0001-8">spreads through the human body</a>.</p>
<p><em>S. pneumoniae</em> is a bacteria that can quickly develop antibiotic resistance. Each year it causes <a href="https://emedicine.medscape.com/article/225811-overview#a8">millions of infections and about one million deaths</a>. Its “ecological niche”, which refers to the natural position of a species within an ecosystem, is our noses and throats, where it doesn’t cause disease.</p>
<p>But from there, <em>S. pneumoniae</em> can spread into the lungs, blood and brain, or more locally into the ear, to cause diseases such as pneumonia, <a href="https://www.healthline.com/health/bacteremia">bacteremia</a>, <a href="https://www.healthdirect.gov.au/meningitis">meningitis</a> and <a href="https://www.healthdirect.gov.au/otitis-media">otitis media</a> (middle ear inflammation).</p>
<p>Unfortunately, <em>S. pneumoniae</em> is a <a href="https://www.asmscience.org/content/journal/microbiolspec/10.1128/microbiolspec.GPP3-0025-2018">genetically diverse pathogen</a>, which means it has many different strains. This complicates research efforts to identify how the bacteria spreads into specific sites of the body.</p>
<p>New research <a href="https://www.nature.com/articles/s42003-020-1018-x?fbclid=IwAR25KbOp_QtjMxu75Y1d6q_bQjzXjNbr-sgkiDFKepRXooLhesy006I63ng">published today in Nature Communications Biology</a> by my colleagues and I circumvented these genetic diversity issues by studying closely related strains of <em>S. pneumoniae</em>. We discovered a difference in a gene between two bacterial strains that regulated their use of raffinose, and this resulted in one being more likely to spread and cause disease.</p>
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Read more:
<a href="https://theconversation.com/scientists-still-searching-for-causes-of-mysterious-pneumonia-outbreak-in-china-130129">Scientists still searching for causes of mysterious pneumonia outbreak in China</a>
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<h2>Sickly sweet, sugars and bacterial disease</h2>
<p>In our <a href="https://mbio.asm.org/content/10/1/e02596-18">previous research</a>, two closely related strains of <em>S. pneumoniae</em> were isolated, one from the blood of a patient and another from the ear. Their sequenced genomes were aligned to pick out differences that may impact how they spread to different parts of the body, and hence how they cause disease. </p>
<p>We found a difference in the regulating gene <em>rafR</em> which is responsible for raffinose uptake. This difference allowed the bacteria in the blood sample to use raffinose more efficiently than in the ear sample. </p>
<p>When infecting mice lungs with <em>S. pneumoniae</em> through their nose, we found the blood sample remained in the lungs, causing invasive disease. However, the ear sample was cleared from the lungs, and was unable to cause disease.</p>
<p>Remarkably, swapping the <em>rafR</em> gene between the strains switched their ability to use raffinose, and the way the disease progressed in each case reversed too. This confirmed the <em>rafR</em> gene was indeed playing a large role in causing disease.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/339968/original/file-20200605-176585-umouop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/339968/original/file-20200605-176585-umouop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/339968/original/file-20200605-176585-umouop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=407&fit=crop&dpr=1 600w, https://images.theconversation.com/files/339968/original/file-20200605-176585-umouop.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=407&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/339968/original/file-20200605-176585-umouop.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=407&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/339968/original/file-20200605-176585-umouop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=511&fit=crop&dpr=1 754w, https://images.theconversation.com/files/339968/original/file-20200605-176585-umouop.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=511&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/339968/original/file-20200605-176585-umouop.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=511&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"><em>Streptococcus pneumoniae</em> imaged with a scanning electron microscope. This bacteria is a major cause of pneumonia. When present in the nose or throat (its ‘ecological niche’) it benefits from the human body without harming it.</span>
<span class="attribution"><a class="source" href="https://wellcomecollection.org/works/xuqru2dc">Debbie Marshall</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
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<p>In our most recent work, we wanted to figure out how this sugar-regulating gene was so profoundly impacting disease progression. </p>
<p>Using a <a href="https://doi.org/10.1038/s42003-%20020-1018-x">cutting-edge sequencing technique</a> during live mice infections, we discovered the difference in the <em>rafR</em> gene altered how both the mice and the bacteria responded to infection. Notably, strains containing the <em>rafR</em> from the ear sample resulted in more neutrophils, an important immune cell, at the site of infection. </p>
<p>In experiments where neutrophils were depleted in the lungs, the ear sample was not cleared, and the risk of disease was more. This research highlights how this single difference in the gene increased neutrophil levels during infection, preventing <em>S. pneumoniae</em> from causing invasive disease.</p>
<h2>Potential research impacts</h2>
<p>Raffinose is mainly found in vegetables, grains and legumes. It’s not known whether the human body ever has high enough levels of it to dramatically impact the likelihood of disease. It may be a carbohydrate similar in structure to raffinose is activating the raffinose regulator <em>rafR</em> instead.</p>
<p>Nonetheless, our research provides insight into how <em>S. pneumoniae</em> causes disease. As we understand what enables this deadly bacteria’s spread through the body, more paths will open up to stopping it. </p>
<p>If this raffinose phenomenon proves to be widespread across <em>S. pneumoniae</em> strains, blocking their ability to use raffinose may prevent them from surviving in, and thus invading, the lungs.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/339970/original/file-20200605-176580-1arm711.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/339970/original/file-20200605-176580-1arm711.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/339970/original/file-20200605-176580-1arm711.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=588&fit=crop&dpr=1 600w, https://images.theconversation.com/files/339970/original/file-20200605-176580-1arm711.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=588&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/339970/original/file-20200605-176580-1arm711.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=588&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/339970/original/file-20200605-176580-1arm711.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=739&fit=crop&dpr=1 754w, https://images.theconversation.com/files/339970/original/file-20200605-176580-1arm711.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=739&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/339970/original/file-20200605-176580-1arm711.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=739&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This illustration depicts a gram stained specimen under a microscope, with a number of <em>Streptococcus pneumoniae</em> bacteria (the small black dashes).</span>
<span class="attribution"><a class="source" href="https://phil.cdc.gov/Details.aspx?pid=2111">CDC</a></span>
</figcaption>
</figure>
<p>Treatments that prevent <em>S. pneumoniae</em> from spreading around the body may be better for preventing disease compared to simply inhibiting or killing the bacteria, as is current practice. </p>
<p><em>S. pneumoniae</em> can stay in our nose and throats, where it does not cause disease. It plays an import role in this ecosystem. When this bacteria is killed, other deadly bacteria may take its place and spread to sites such as the lungs to cause disease.</p>
<h2>The risk in failing to find new treatments</h2>
<p><em>S. pneumoniae’s</em> ability to rapidly develop antibiotic resistance has led the <a href="https://www.who.int/news-room/detail/27-02-2017-who-publishes-list-of-bacteria-for-which-new-antibiotics-are-urgently-needed">World Health Organisation</a> and <a href="https://www.cdc.gov/drugresistance/biggest-threats.html">US Centres for Disease Control and Prevention</a> to list it as a priority pathogen. </p>
<p>Though vaccines are available, they’re far from perfect and fail to cover all the different strains of <em>S. pneumoniae</em>. If new treatments and vaccines aren’t created soon, the already deadly impact of this bacteria may increase. </p>
<p>Despite the known dangers, research into discovering new antibiotics has been slow. Many treatments in the pipeline <a href="https://www.who.int/news-room/detail/17-01-2020-lack-of-new-antibiotics-threatens-global-efforts-to-contain-drug-resistant-infections">don’t provide much benefit over existing antibiotics</a>. Also, effective new treatments usually aren’t implemented widely, and are instead used as a back up in case all else fails. This greatly reduces their profitability, which in turn decreases incentives to make them. </p>
<p>In a worst case scenario, antibiotic-resistant bacteria could kill up to <a href="https://www.who.int/news-room/detail/29-04-2019-new-report-calls-for-urgent-action-to-avert-antimicrobial-resistance-crisis">ten million people each year by 2050</a>. To avoid such catastrophe, more research is needed on how bacteria cause disease. And with this knowledge we may be able to lessen the likelihood of future pandemics. </p>
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Read more:
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<p class="fine-print"><em><span>Vikrant Minhas is a co-founder of the space research company ResearchSat</span></em></p>S. pneumoniae, the bacteria responsible for pneumonia, causes about one million deaths each year. Now we know how it uses the sugar raffinose to spread through the body to cause disease.Vikrant Minhas, PhD candidate, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1181022019-07-12T12:06:07Z2019-07-12T12:06:07ZTicks spread plenty more for you to worry about beyond Lyme disease<figure><img src="https://images.theconversation.com/files/283715/original/file-20190711-173334-1u1skq3.jpg?ixlib=rb-1.1.0&rect=404%2C134%2C3325%2C2317&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">There's a short window between when a tick bites and when it passes on bacteria or virus.</span> <span class="attribution"><span class="source">MSU Ag Communications, Courtesy Dr. Tina Nations</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>When it comes to problems caused by ticks, Lyme disease hogs a lot of the limelight. But various tick species carry and transmit a collection of other pathogens, some of which cause serious, even fatal, conditions.</p>
<p>In fact, the <a href="https://doi.org/10.1016/j.pt.2012.07.003">number of tick-borne disease cases is on the rise</a> in the United States. The range where various species of ticks live in North America may be <a href="http://dx.doi.org/10.1155/2009/593232">expanding due to climate change</a>. Researchers continue to discover <a href="https://doi.org/10.1128/microbiolspec.EI10-0012-2016">new pathogens that live in ticks</a>. And <a href="https://www.cdc.gov/ticks/longhorned-tick/index.html">new, invasive tick species</a> keep turning up.</p>
<p>In <a href="https://scholar.google.com/citations?user=JVfeckwAAAAJ&hl=en&oi=ao">my career as a</a> <a href="https://doi.org/10.1201/b12686">public health entomologist</a>, I’ve been amazed at the ability of ticks to bounce back from all the ways people try to control them, including with pesticides. Ticks excel at finding new ecological niches for survival. So people and ticks frequently cross paths, exposing us to their bites and the diseases they carry.</p>
<p>Here are some of the lesser-known, but growing, threats from ticks.</p>
<h2>Ticks can spread bacterial diseases</h2>
<p>Certain very small species of bacteria that can cause human diseases, such as rickettsia, ehrlichia and anaplasma, live in ticks. Ticks ingest these bacteria when they drink animals’ blood. Then when the ticks take a subsequent blood meal, they pass the bacteria along to the next animal or person they feed on.</p>
<p>Probably the most well known of these bacterial diseases is <a href="https://www.cdc.gov/rmsf/index.html">Rocky Mountain spotted fever</a>, the most frequently reported rickettsial disease in the U.S., with <a href="https://wonder.cdc.gov/nndss/static/2017/annual/2017-table1.html">about 6,000 cases each year</a>. The number of diagnoses seems to be increasing nationwide, <a href="https://doi.org/10.4269/ajtmh.2009.80.601">especially among Native Americans</a>, probably due to exposure on reservations to free-roaming dogs that can carry ticks.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/278758/original/file-20190610-52758-1y6uqpg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/278758/original/file-20190610-52758-1y6uqpg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/278758/original/file-20190610-52758-1y6uqpg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=385&fit=crop&dpr=1 600w, https://images.theconversation.com/files/278758/original/file-20190610-52758-1y6uqpg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=385&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/278758/original/file-20190610-52758-1y6uqpg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=385&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/278758/original/file-20190610-52758-1y6uqpg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=484&fit=crop&dpr=1 754w, https://images.theconversation.com/files/278758/original/file-20190610-52758-1y6uqpg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=484&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/278758/original/file-20190610-52758-1y6uqpg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=484&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rocky Mountain spotted fever usually comes with a rash, as on this child.</span>
<span class="attribution"><a class="source" href="https://phil.cdc.gov/Details.aspx?pid=1962">Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases (NCIRD)</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>When people get sick with Rocky Mountain spotted fever, they usually come to a clinic with three things: fever, rash and history of tick bite. They may also report severe headache, chills and muscle pains, and gastrointestinal symptoms such as abdominal pain and diarrhea. A skin rash is usually present after a few days, but not always. Mental confusion, coma and death can occur in severe cases. Untreated, the mortality rate is about 20%; and even with treatment, 4% of those infected die.</p>
<p>Not all tick species are effective transmitters of the rickettsia bacteria. Even within the vector species, often <a href="https://doi.org/10.1056/NEJMoa050043">only 1% to 5% of ticks in an area are infected</a>. So getting bitten by a tick that passes rickettsia bacteria on to you is like getting stuck with a needle in a haystack. The primary carriers are the American dog tick in the eastern U.S. and Rocky Mountain wood tick in the West. The brown dog tick has also recently been <a href="http://dx.doi.org/10.15585/mmwr.rr6502a1">shown to be a vector</a>. </p>
<p>In most tick-borne diseases, the <a href="https://jcm.asm.org/content/25/3/557.short">tick needs to feed for some amount of time</a> before any pathogens it’s carrying are transmitted to the animal whose blood it’s eating. Rocky Mountain spotted fever organisms generally take between one and three hours for transmission to occur, so attached ticks need to be removed quickly. Doctors usually prescribe the antibiotic doxycycline to treat Rocky Mountain spotted fever, which works quite well if the disease is recognized early.</p>
<p><iframe id="hCzmS" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/hCzmS/3/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p><a href="https://www.cdc.gov/ehrlichiosis/index.html">Ehrlichiosis</a> is another bacterial disease transmitted from ticks to people. In the U.S. it’s most commonly caused by <em>Ehrlichia chaffeensis</em> bacteria, carried by lone star ticks which are common in the eastern U.S. Ehrlichia bacteria infect a type of blood cell called leukocytes. Human monocytic ehrlichiosis occurs mostly in the southern and south-central U.S.; <a href="https://wonder.cdc.gov/nndss/static/2017/annual/2017-table1.html">1,642 cases were reported</a> to the CDC in 2017. </p>
<p>Ehrlichiosis patients usually have fever, headache, muscle aches and a progressive low white blood cell count. As opposed to Rocky Mountain spotted fever, people get a rash only about 20% to 40% of the time. Doctors usually treat ehrlichiosis with doxycycline.</p>
<p>Another tick-borne bacterial disease to worry about is <a href="http://dx.doi.org/10.15585/mmwr.rr6502a1">human granulocytic anaplasmosis</a>. In human granulocytic anaplasmosis, <em>Anaplasma phagocytophilum</em> bacteria infects a type of white blood cell called granulocytes. It mostly occurs in the upper midwestern and northeastern U.S., and the incidence is increasing, with <a href="https://wonder.cdc.gov/nndss/static/2017/annual/2017-table1.html">5,762 cases of human granulocytic anaplasmosis reported</a> to the CDC in 2017.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/283720/original/file-20190711-173370-18run1w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/283720/original/file-20190711-173370-18run1w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/283720/original/file-20190711-173370-18run1w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/283720/original/file-20190711-173370-18run1w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/283720/original/file-20190711-173370-18run1w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/283720/original/file-20190711-173370-18run1w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/283720/original/file-20190711-173370-18run1w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/283720/original/file-20190711-173370-18run1w.jpg?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">A female <em>Ixodes scapularis</em> tick.</span>
<span class="attribution"><span class="source">Dr. Blake Layton, MSU</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Symptoms include fever, headache, muscle aches and progressive low white blood cell count. It’s the deer tick <em>Ixodes scapularis</em> – famously also responsible for Lyme disease – that transmits the Anaplasma bacteria to humans. There’s the unlucky chance that a bite from a deer tick could infect you with both diseases. Again, recommended therapy is doxycycline.</p>
<h2>Ticks can carry viruses, too</h2>
<p>People usually think of mosquitoes when they think of insect-transmitted viruses – dengue, Zika or West Nile garner a lot of headlines. But ticks can transmit viruses, too.</p>
<p>Scientists have historically grouped tick-borne viral diseases into two categories. One is diseases similar to dengue fever. The main dengue-like viral disease transmitted by ticks in the U.S. is <a href="https://www.ncbi.nlm.nih.gov/pubmed/19954">Colorado tick fever</a>, which occurs in mountainous areas of the West.</p>
<p>The other group of tick-borne diseases resemble mosquito-borne encephalitis. Most of these illnesses, characterized by brain inflammation, are not found in the U.S. <a href="https://doi.org/10.1146/annurev-ento-112408-085446">Powassan encephalitis is the one that is</a>, occurring in the northeastern U.S. and adjacent regions of Canada.</p>
<p>Powassan is a relatively rare but serious human disease, characterized by sudden onset of fever with temperature up to 104 degrees Fahrenheit, along with convulsions. Brain inflammation is usually severe, with vomiting, respiratory distress and prolonged fever.</p>
<p><a href="https://wonder.cdc.gov/nndss/static/2017/annual/2017-table1.html">Fewer than 100 cases of Powassan have been reported</a> in North America, with about half of them fatal. Its incidence seems to be increasing; there were 34 cases of Powassan reported during 2017. POW is maintained in a natural cycle when ticks – primarily <em>Ixodes cookei</em> – infect animals with the virus via their bites. Then these infected animals may serve as what scientists call <a href="https://en.wikipedia.org/wiki/Natural_reservoir">disease reservoirs</a>, infecting new ticks when they feed on their blood.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/283723/original/file-20190711-173347-19l9cwa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/283723/original/file-20190711-173347-19l9cwa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/283723/original/file-20190711-173347-19l9cwa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=412&fit=crop&dpr=1 600w, https://images.theconversation.com/files/283723/original/file-20190711-173347-19l9cwa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=412&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/283723/original/file-20190711-173347-19l9cwa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=412&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/283723/original/file-20190711-173347-19l9cwa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=517&fit=crop&dpr=1 754w, https://images.theconversation.com/files/283723/original/file-20190711-173347-19l9cwa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=517&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/283723/original/file-20190711-173347-19l9cwa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=517&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Tiny larval lone star ticks next to a penny.</span>
<span class="attribution"><span class="source">Jerome Goddard</span></span>
</figcaption>
</figure>
<p>In the last decade, researchers have found additional new tick-borne viruses in the U.S. About <a href="https://europepmc.org/articles/pmc5779346">30 cases of Heartland virus</a> have thus far been identified. It’s associated with the lone star tick and has been recognized in Missouri, Oklahoma, Kentucky and Tennessee.</p>
<p>A few cases of a new Thogotovirus <a href="https://doi.org/10.3201/eid2312.170532">called Bourbon virus</a> have been identified in the Midwest and southern U.S. The lone star tick may be the vector of Bourbon virus as well.</p>
<h2>A food allergy triggered by a tick bite</h2>
<p>Maybe the most bizarre threat from ticks is the “<a href="https://doi.org/10.1097/ACI.0b013e3283624560">red meat allergy</a>” scientists have recently traced back to tick bites. People can become allergic to eating meat when a tick’s saliva passes on the carbohydrate galactose-α-1.3-galactose it had previously picked up in a blood meal from an animal. If prone to allergies, the person can get sensitized to that alpha-gal molecule that’s found in animal blood and other tissues.</p>
<p>Then days or weeks later, he or she may develop hives, swollen skin and lips, or even life-threatening anaphylactic shock three to six hours after eating red meat. Meats containing alpha-gal include beef, pork, lamb, squirrel, rabbit, horse, goat, deer, kangaroo, seal and whale. People who become sensitized to alpha-gal may still eat chicken, turkey and fish.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/283738/original/file-20190711-173347-3jgt7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/283738/original/file-20190711-173347-3jgt7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/283738/original/file-20190711-173347-3jgt7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/283738/original/file-20190711-173347-3jgt7f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/283738/original/file-20190711-173347-3jgt7f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/283738/original/file-20190711-173347-3jgt7f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/283738/original/file-20190711-173347-3jgt7f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/283738/original/file-20190711-173347-3jgt7f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Take precautions, like tucking pants into socks, when you’re in tick territory.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/protecting-against-ticks-by-tucking-pants-322456178?studio=1">rck_953/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>Overall, people should be aware of what tick-borne diseases are present in their area and use <a href="https://www.cdc.gov/ticks/avoid/on_people.html">personal protection techniques</a> whenever outdoors in tick-infested areas. Remember that ticks often come into close contact with people via pet dogs or cats. It’s a good idea to inspect yourself for ticks after being outdoors in tick-infested areas. Reducing the number of tick bites and the amount of time ticks remain attached can go a long way to protecting you from tick-borne diseases.</p>
<p>[ <em>You’re smart and curious about the world. So are The Conversation’s authors and editors.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=youresmart">You can read us daily by subscribing to our newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/118102/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jerome Goddard 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>Tick-borne diseases are becoming more common in the United States. A public health entomologist outlines some of the lesser-known threats ticks pose to human health.Jerome Goddard, Extension Professor of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/954992018-04-24T10:53:48Z2018-04-24T10:53:48ZWhy are some ‘E. coli’ deadly while others live peacefully within our bodies?<figure><img src="https://images.theconversation.com/files/216041/original/file-20180424-94157-1hsgfxd.jpg?ixlib=rb-1.1.0&rect=98%2C71%2C2793%2C1859&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">From a human perspective, some strains are good, some are evil.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/e-coli-bacteria-close-72915928">fusebulb/Shutterstock.com</a></span></figcaption></figure><p><em>E. coli</em> outbreaks hospitalize people and cause food recalls pretty much annually in the United States. <a href="https://www.cdc.gov/ecoli/2018/o157h7-04-18/index.html">This year is no different</a>. </p>
<p>Obviously some <em>E. coli</em> can be deadly for people. But not all strains of these bacteria make you sick. In fact, you have a variety of strains of <em>E. coli</em> in your intestines right now – including one that’s <a href="https://doi.org/10.1016/0006-2952(72)90184-0">busy making the antioxidant vitamin K</a>, crucial for your and its survival.</p>
<p>Scientists <a href="https://scholar.google.com/citations?user=kyNhp3UAAAAJ&hl=en&oi=ao">like me</a> often characterize <em>E. coli</em> by the sugar coat they display on their cell surface. A molecule called a lipopolysaccharide is the anchor that displays a collection of sugars to their environment. </p>
<p>These sugars help the bacteria stick to surfaces and reveal their identity to your immune system. Human cells do this, too – your blood type is defined by sugars displayed on your blood cells, for instance.</p>
<p>The sugars <em>E. coli</em> display vary from strain to strain. Some sugar coats are associated with strains living symbiotically in your stomach – <em>E. coli</em> HS, UTI89 and CFT073 are some of the most commonly found to be helpful. Others are associated with illness – like <em>E. coli</em> O104:H4, also called enterohemorrhagic <em>E. coli</em> (EHEC), which caused a <a href="https://www.britannica.com/event/German-E-coli-outbreak-of-2011">major outbreak in Europe in 2011</a>. According to the CDC, this latest outbreak is due to <em>E. coli</em> O157:H7 – a strain that’s caused at least one food-borne outbreak in the U.S. each year since 2006.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/216039/original/file-20180424-94118-17qf7qx.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/216039/original/file-20180424-94118-17qf7qx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/216039/original/file-20180424-94118-17qf7qx.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216039/original/file-20180424-94118-17qf7qx.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216039/original/file-20180424-94118-17qf7qx.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216039/original/file-20180424-94118-17qf7qx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=378&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216039/original/file-20180424-94118-17qf7qx.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=378&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216039/original/file-20180424-94118-17qf7qx.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=378&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A simplified diagram shows the lipopolysaccharide sugars on the exterior of a bacterium’s cell wall.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Gram_negative_cell_wall.svg">Jeff Dahl</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The letters and numbers that name a strain serve as a code for which sugars are present. While the sugars bacteria display aren’t what makes you sick, they’re quickly and easily detectable and help scientists and doctors differentiate whether a present strain will generate toxins that can make you ill.</p>
<p>Bacteria rely on what researchers term virulence factors: molecules that aid their survival while undermining your immune system. Both the EHEC and O157 strains of <em>E. coli</em> are able to make a virulence factor called a Shiga toxin. <a href="https://doi.org/10.1128/microbiolspec.EHEC-0024-2013">Shiga toxins were discovered</a> first in <em>Shigella dysenteriae</em>, the bacterium that causes dysentery. Later researchers discovered that the EHEC and O157 strains of <em>E. coli</em> <a href="https://doi.org/10.1016/j.cll.2009.11.001">had gained the gene for Shiga toxins</a> from the dysentery bacterium through a process called <a href="https://www.britannica.com/science/horizontal-gene-transfer">horizontal gene transfer</a>.</p>
<p>When bacteria reach a critical mass in your body after you eat a contaminated food, they secrete these toxins as part of their strategy for finding a new host. The toxins enter the cells of your intestines, causing symptoms including low-grade fever, stomach cramps, diarrhea (often bloody) and vomiting.</p>
<p>It’s virulence factors like these that are to blame for human illnesses and that give <em>E. coli</em> a bad name – even if all strains don’t deserve it.</p><img src="https://counter.theconversation.com/content/95499/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Erika A. Taylor receives funding from the National Institutes of Health (NIH). </span></em></p>E. coli bacteria are the frequent culprits behind outbreaks of food-borne illnesses. But not all strains are harmful; some are even helpful.Erika A. Taylor, Associate Professor of Chemistry and Environmental Studies, Wesleyan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/912552018-02-14T16:27:02Z2018-02-14T16:27:02ZHow Cape Town’s water crisis could make people sick<figure><img src="https://images.theconversation.com/files/205076/original/file-20180206-14111-3hiybr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Reuters/ Mike Hutchings </span></span></figcaption></figure><p><a href="http://earthsky.org/earth/day-zero-approaches-as-cape-towns-water-runs-out">Day zero</a>, when the 4 million people living in Cape Town run out of water, is becoming a real possibility. The city has informed residents that water supplies will be turned off on the day and only retained for high risk areas and essential services. Citizens will have to queue for water at key points of distribution. </p>
<p>This scenario will affect businesses, the economy, education, recreation and social life. It will also have significant implications for the health of people living in Cape Town. The city therefore needs to put plans in place to reduce the risks. </p>
<p>The immediate health effects can be categorised into three main areas. Pressure on the sanitation system which raises the prospect of the spread of life threatening diseases such as dysentery; loss of hygiene because people can’t wash their hands; dehydration and heat strokes. In addition, there could be other consequences such as stress levels spiking and people becoming violent as they try and access water or over stretched health facilities. </p>
<h2>Not being able to flush</h2>
<p>Firstly, the city depends on a waterborne sewage system and the inability to flush toilets may lead to a breakdown in sanitation. People may be unable to dispose of faecal waste easily and may resort to disposing of their faeces outside. Many viral, bacterial and <a href="https://euromd.com/9-diseases-and-conditions/134-diseases-and-treatment/27-infectious-and-parasitic-diseases/post-5543-protozoal-diseases-causes-symptoms-and-treatment/">protozoal diseases</a> are spread in the faeces and the risk of environmental contamination will significantly increase. Infectious diseases that cause diarrhoea, vomiting or dysentery, such as enteroviruses, salmonella, shigella, or E Coli, will be more likely. </p>
<p>In addition, viral hepatitis may also be transmitted in faeces. In other parts of Africa, a breakdown in sanitation has led to outbreaks of infectious diseases. Recently, the City has faced a number of disease outbreaks such as <a href="https://www.healthline.com/health/diphtheria">diphtheria</a> and <a href="https://wwwnc.cdc.gov/travel/diseases/typhoid">typhoid</a> –- it is important to present early to health facilities if an infectious disease is suspected, especially in children.</p>
<h2>Not being able to wash</h2>
<p>Secondly, the absence of water in taps, wash basins and showers may lead to a loss of hygiene. Skin infections such as impetigo and infestations such as scabies may increase as well as conjunctivitis. A reduction in effective hand washing may also increase the spread of acute respiratory viruses that cause coughs, colds, ‘flu like illnesses, bronchitis and pneumonia. </p>
<p>A loss of sanitation and hygiene may also lead to an increase in hand-to-mouth transmission of infectious diseases that cause diarrhoea, vomiting and dysentery as outlined above. A lack of hand hygiene and water to clean food may also lead to an increase in food-borne diarrheal diseases. </p>
<p>People with immune deficiencies, such as those with HIV or who are malnourished, may be particularly at risk as well as small babies and the elderly. An increased incidence of diarrhoeal diseases will have a negative impact on childhood nutrition in vulnerable communities.</p>
<h2>Not enough to drink, and other consequences</h2>
<p>Thirdly, the absence of a readily available water supply may predispose people to dehydration and heat stroke. Children are particularly vulnerable especially if they contract diarrhoea. This would also be a particular risk on very hot days and to those performing manual labour without an adequate supply of fluids. In addition people may be tempted to drink contaminated or non-potable water if they cannot afford to buy water or cannot easily access points of distribution.</p>
<p>Lastly, there may be conflict over water as a scarce resource and an increase in unrest, violence and injuries. And some businesses may be unable to function without a water supply and people may lose their income or jobs. This may place increased psycho-social stress on communities and have consequences for mental health as well as harmful alcohol use. </p>
<p>Conflict could also break out at health facilities as waiting times and staff workload increase because of a spike in illnesses.</p>
<h2>What are the authorities planning</h2>
<p>To deal with these challenges, various bodies in the City of Cape Town are working together to respond appropriately. </p>
<p>For example, the <a href="http://resource.capetown.gov.za/documentcentre/Documents/Procedures%2c%20guidelines%20and%20regulations/Disaster%20and%20Demand%20FAQ.pdf">city</a> is working with the police and the National Defence Force to ensure that order is maintained when day zero arrives.</p>
<p>From an environmental health perspective, there are routine systems in place to monitor and respond to outbreaks in the city. Surveillance for outbreaks will be enhanced over this period. </p>
<p>But the water supply to most health facilities will be maintained to enable them to manage ill patients, outbreaks and cases of dehydration. </p>
<p>Water will also be supplied through designated distribution points to limit the risk of dehydration, maintain hygiene standards and enable the flushing of toilets through the use of grey water. Areas that are at a high risk of outbreaks such as informal settlements will have their water supply maintained. This will assist with these areas to dispose faeces. </p>
<p>Residents are still being encouraged to wash or sanitise their hands to reduce the risk of infectious diseases spreading.</p><img src="https://counter.theconversation.com/content/91255/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>When day zero arrives in Cape Town, the routine surveillance systems that monitor disease outbreaks will be enhanced to pick up new diseases.Bob Mash, Division of Family Medicine and Primary Care, Stellenbosch UniversityHassan Mahomed, Public Health Specialist in the Division of Health Systems and Public Health,, Stellenbosch UniversityShrikant Peters, Public Health Registrar in the Division of Public Health Medicine, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.