tag:theconversation.com,2011:/us/topics/contentious-diseases-26891/articlesContentious diseases – The Conversation2016-04-21T06:53:58Ztag:theconversation.com,2011:article/577172016-04-21T06:53:58Z2016-04-21T06:53:58ZExplainer: what is Lyme disease and does it exist in Australia?<figure><img src="https://images.theconversation.com/files/119496/original/image-20160420-25625-1wyrzv.jpg?ixlib=rb-1.1.0&rect=19%2C0%2C2514%2C1555&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">No, not that kind of lime: the disease is named after a town in the US where the disease was first recognised.</span> <span class="attribution"><span class="license">Author provided</span></span></figcaption></figure><p>Ticks in Australia are a health risk. Reactions to their bites can be severe; they can cause life-threatening paralysis and allergies and transmit disease-causing pathogens. But it is the debate about Lyme disease and its presence in Australia that has occupied media headlines and the minds of scientists and health professionals for more than three decades.</p>
<h2>What is Lyme disease?</h2>
<p>Lyme disease (also known as Lyme borreliosis) is caused by the bacteria <em>Borrelia burgdorferi sensu lato</em>. Cases are reported from <a href="http://www.cdc.gov/lyme">North America</a>, <a href="http://ecdc.europa.eu/en/healthtopics/emerging_and_vector-borne_diseases/tick_borne_diseases/lyme_disease/pages/index.aspx">Europe</a> and temperate regions of <a href="http://wwwnc.cdc.gov/travel/yellowbook/2016/infectious-diseases-related-to-travel/lyme-disease">northern Asia</a>.</p>
<p>Symptoms associated may include a distinctive “bullseye”-shaped rash, followed by flu-like symptoms (such as fever, headache, sore muscle and joints, fatigue), various neurological manifestations and arthritis. Some forms in Europe can even cause a dermatological condition known as <a href="http://emedicine.medscape.com/article/1051695-overview">acrodermatitis chronica atrophicans</a>, which causes swelling and discolouration of the hands or feet.</p>
<p>Lyme disease is diagnosed based on symptoms, a history of exposure to ticks, and validated laboratory tests. If <a href="http://www.cdc.gov/lyme/treatment/">diagnosed and treated early</a> with appropriate antibiotics, infected individuals have a quick recovery.</p>
<p>Ticks spread the bacteria. The ticks primarily responsible are those commonly known as the “black legged” ticks. The ticks acquire the bacteria through biting small mammals, particularly the mice that are the natural reservoirs of the pathogen. When the tick then bites people, the bacteria are transmitted via the tick saliva.</p>
<h2>Is Lyme disease in Australia?</h2>
<p>The presence in Australia of Lyme disease, or a “Lyme-like” illness, is highly debatable. It has long been a contentious issue fuelled by <a href="http://www.abc.net.au/radionational/programs/backgroundbriefing/2013-05-12/4675072">emotional stories of patients suffering illness</a> following exposure to ticks. However, there remains a lack of any compelling scientific evidence that the pathogen that causes Lyme disease is present in Australia.</p>
<p>The ticks known to transmit <em>Borrelia burgdorferi</em> overseas are not found in Australia, but we certainly have <a href="http://www.biotaxa.org/Zootaxa/article/view/zootaxa.3816.1.1">plenty of local ticks</a>.</p>
<p>The Australian paralysis tick, <em>Ixodes holocyclus</em>, is generally thought to pose the greatest local health risk. The tick bites people, causing allergic reactions ranging from a mild itching with localised swelling, to a <a href="http://emj.bmj.com/content/15/2/111.short">life-threatening anaphylactic condition</a> and the development of a <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4313755/">mammalian meat allergy</a>. <a href="http://www.sciencedirect.com/science/article/pii/002075199190127S">Laboratory studies</a> show this tick cannot transmit <em>Borrelia burgdorferi</em>.</p>
<p>Could another tick species be involved?</p>
<p>Since the 1990s, scientists have searched for <em>Borrelia burgdorferi</em> in local ticks and wildlife but the bacteria have never been definitively detected. Perhaps the tick-borne pathogen responsible for the reported cases of “Lyme-like” illness is yet to be found. Or it simply may not exist.</p>
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<img alt="" src="https://images.theconversation.com/files/119504/original/image-20160420-25621-1xg9vuw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/119504/original/image-20160420-25621-1xg9vuw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119504/original/image-20160420-25621-1xg9vuw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119504/original/image-20160420-25621-1xg9vuw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119504/original/image-20160420-25621-1xg9vuw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119504/original/image-20160420-25621-1xg9vuw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119504/original/image-20160420-25621-1xg9vuw.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">The Australian paralysis tick, <em>Ixodes holocyclus</em></span>
<span class="attribution"><span class="source">Stephen Doggett (NSW Health Pathology)</span></span>
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</figure>
<h2>Reviewing evidence and experience</h2>
<p>In 2013, the Chief Medical Officer of Australia established the <a href="http://www.health.gov.au/internet/main/publishing.nsf/Content/ohp-cacld-lyme-disease.htm">Clinical Advisory Committee on Lyme Disease</a>. The terms of reference broadly covered the examination of the evidence of Lyme disease in Australia. It sought to identify research requirements as well as review the appropriateness of the associated diagnostic testing and treatment of human cases.</p>
<p>The committee was convened for one year. In that time no conclusive evidence was provided that established whether or not a tick-borne pathogen was responsible for suspected Lyme disease cases in Australia.</p>
<p>A recently published <a href="http://www.sciencedirect.com/science/article/pii/S2352771416300039">major review of 25 years of research</a> studied more than 500 cases of Lyme-like illness reported in the scientific literature. The authors conclude that no study to date definitively identifies <em>Borrelia burgdorferi</em> as responsible for locally acquired Lyme disease, or that any of the human cases could be definitely called Lyme disease.</p>
<p>It is impossible to completely discount the possibility that an unidentified tick-borne pathogen is responsible for suspected illness. <a href="http://media.murdoch.edu.au/researchers-closer-to-ending-debate-around-lyme-disease-and-ticks-in-australia">Research continues</a> and <a href="http://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-015-0958-3">emerging technologies</a> will provide opportunities to discover and better understand the microorganisms associated with local ticks.</p>
<p>Without conclusive evidence, debate continues. </p>
<p>A Senate inquiry, “<a href="http://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Community_Affairs/Lyme-like_Illness">Growing evidence of an emerging tick-borne disease that causes a Lyme-like illness for many Australian patients</a>”, has recently begun. With hundreds of submissions received, hearings are being held across the country.</p>
<p>A hurdle may present itself should a <a href="http://www.smh.com.au/federal-politics/political-news/lyme-disease-campaigners-fear-collapse-of-inquiry-with-early-election-20160321-gnnywp.html">double dissolution election be called</a> and the inquiry halted. It must be hoped that the inquiry, supported by the new Senate, will continue following the election. While its fate is uncertain, even if it were to continue, it is unlikely to resolve the issue. </p>
<p>Irrespective of the eventual outcome of the Senate inquiry, or any findings from current or future research, health authorities will continue to warn the community to <a href="http://www.health.gov.au/internet/main/publishing.nsf/Content/ohp-tick-bite-prevention.htm">avoid ticks</a>. </p>
<p>If you do find a tick attached, make sure you follow the recommendations provided by the <a href="http://www.allergy.org.au/">Australasian Society of Clinical Immunology and Allergy</a> (ASCIA) to “<a href="https://theconversation.com/tackling-the-tricky-task-of-tick-removal-26306">freeze not squeeze</a>”. Before removing the tick, use an aerosol “freezing” spray (the type normally used for wart treatments) to rapidly kill the tick. That way you can minimise any potentially serious reactions.</p><img src="https://counter.theconversation.com/content/57717/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cameron Webb and the Department of Medical Entomology, NSW Health Pathology and University of Sydney, have been engaged by a wide range of insect repellent and insecticide manufacturers to provide testing of products and provide expert advice on biting arthropod biology. Cameron has also received funding from local, state and federal agencies to undertake research into vector-borne disease surveillance and management.</span></em></p>The debate about Lyme disease and its presence in Australia has occupied media headlines and the minds of scientists and health professionals for over three decades.Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/172042014-01-09T04:29:27Z2014-01-09T04:29:27ZExplainer: what is chronic fatigue syndrome?<figure><img src="https://images.theconversation.com/files/35772/original/s4zx7nn5-1385008450.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Chronic fatigue is often misunderstood by the general public and medical professionals alike</span> <span class="attribution"><span class="source">Flickr / Arne Coormans</span></span></figcaption></figure><p>Chronic fatigue syndrome, or myalgic encephalomyelitis, is a highly debilitating, but often misunderstood, disorder. </p>
<p>As its name suggests, the illness is characterised by profound fatigue, muscle and joint pain, and impaired memory and concentration. Sufferers also experience impaired cardiovascular function, gut disorders, and sensory dysfunction, such as noise intolerance and problems with balance. </p>
<p>The symptoms tend to be so deliberating and severe that chronic fatigue patients often experience family and social breakdown and isolation. Many cases can continue for months or years, and often symptoms don’t improve with rest.</p>
<p>Chronic fatigue syndrome was trivialised for years due to the lack of scientific evidence supporting its diagnosis, and dismissed as the “yuppie flu”. Sufferers continue to endure the stigma of a condition that is often poorly recognised by the medical community and treated with scepticism by family, friends, and co-workers. </p>
<p>All this despite the fact that chronic fatigue is thought to have a global prevalence rate of <a href="http://www.cfids-cab.org/cfs-inform/Reviewcfs/bassi.etal08.pdf">0.2 to 2.6% </a>. A <a href="http://www.mecfs.org.au/what-is-meorcfs">conservative estimate</a> puts the number of people in Australia with chronic fatigue disorder at 180,000. </p>
<p>Chronic fatigue predominantly affects young adults between the ages of 20 and 40 years. The female-to-male diagnosis ratio is six-to-one but why the disorder is more prevalent in women than men is unknown. </p>
<p>Managing chronic fatigue syndrome can be as complex as the illness itself. There is no cure and no prescription drugs have been developed specifically for chronic fatigue syndrome, making it very difficult to treat. Symptoms can also vary over time. </p>
<p>People with chronic fatigue syndrome should closely monitor their health in conjunction with their doctor to create an individualised treatment program that best meets their needs. This program should be based on a combination of therapies that address symptoms, coping techniques and ways to manage normal daily activities.</p>
<p>It’s crucial that we discover a biological basis for chronic fatigue so we can start working out ways to better treat the condition. </p>
<p>Diagnosis is a <a href="http://books.google.com.au/books?id=fuW7l-4lgv8C&pg=PA27&lpg=PA27&dq=Lloyd+1992+annual+costs+of+cfs&source=bl&ots=BM-FxX0fjF&sig=GqXov6ay1zLYXh6mZjcI28QKCJM&hl=en&sa=X&ei=DVKuUo2HOIL-iAf-44CwBQ&ved=0CC4Q6AEwAA#v=onepage&q=Lloyd%201992%20annual%20costs%20of%20cfs&f=false">lengthy and expensive process</a>, as a host of other diseases that share symptoms have to be excluded. Given that diagnosis is notoriously difficult, finding unique markers of the illness has been a focus of research for over 20 years. </p>
<p>Researchers have observed <a href="http://www.translational-medicine.com/content/9/1/81">significant differences</a> between the immune cells of chronic fatigue sufferers and healthy people. This discovery could potentially lead to the identification of chronic fatigue biomarkers (examinable biological indicators that can be used for diagnosis). </p>
<p>This, in turn, could lead to the development of tests that detect chronic fatigue rather than having to rely on reported symptoms.</p>
<p><a href="http://chronicfatigue.stanford.edu/">Other researchers</a> have identified a strong association between chronic fatigue syndrome and a deregulated (or ill-functioning) immune system, which might point to the underlying mechanism of the disorder. </p>
<p>In sufferers of chronic fatigue, the researchers observed that the function of “natural killer cells” — immune cells that have the ability to kill off infected cells in the body – was reduced. This means they’re unable to remove pathogens effectively and efficiently. </p>
<p>And Australian researchers have <a href="http://www.omicsonline.org/immune-abnormalities-in-patients-meeting-new-diagnostic-criteria-for-chronic-fatigue-syndromemyalgic-encephalomyelitis-2155-9929.1000152.pdf">discovered changes</a> in a number of other immune cells that are required to fight viruses in people with chronic fatigue. </p>
<p>In particular, they’ve have identified specific changes to the gene that controls these cells, and the receptors that activate them. This suggests there is a possible explanation as to why these cells are able not functioning effectively and efficiently.</p>
<p>Collectively, these results provide the first steps towards a system for the early diagnosis of chronic fatigue. They may also provide evidence that these changes in immune function are involved in the cause of the disorder. </p>
<p>But while the findings have the potential to bring relief to many chronic fatigue sufferers, research is still in its preliminary stages. At this juncture, researchers are testing these potential biomarkers against a number of other diseases to ensure they’re unique to chronic fatigue syndrome patients.</p>
<p>With a better understanding of the biological causes of chronic fatigue, we can not only tackle the symptoms of chronic fatigue, but the stigma as well.</p><img src="https://counter.theconversation.com/content/17204/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sonya Marshall-Gradisnik receives funding from Mason Foundation, Edward P Evans Foundation and the Queensland Government -Smart State Initiatives.</span></em></p>Chronic fatigue syndrome, or myalgic encephalomyelitis, is a highly debilitating, but often misunderstood, disorder. As its name suggests, the illness is characterised by profound fatigue, muscle and joint…Sonya Marshall-Gradisnik, Chief researcher, School of Medical Science, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2982011-04-08T04:18:33Z2011-04-08T04:18:33ZADHD, autism or something else entirely?<figure><img src="https://images.theconversation.com/files/370/original/aapone-20090502000176459433-britain-health-swine-flu-detection-test-original.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A DNA test can detect fragile X syndrome with 99% accuracy.</span> <span class="attribution"><span class="source">AAP</span></span></figcaption></figure><p>Most people are not aware of fragile X syndrome but they may well be affected by it or know someone who is. Commonly under-diagnosed or misdiagnosed the condition is often mistaken for Attention Deficit Hyperactive Disorder (ADHD) or autism. </p>
<p>Prevalence of 1 in 2500 worldwide makes the syndrome the world’s most common cause of hereditary developmental difficulties in children. </p>
<p>Its effect is gender-specific with girls usually showing milder levels of intellectual difficulty than boys. </p>
<p>Caused by an abnormal expansion of DNA just above the tip of the X chromosome’s long arm, fragile X occurs across every culture. And unlike similar disorders, it is not related to the age of the mother at the time of conception. </p>
<h2>Genetic path of the syndrome</h2>
<p>Fragile X can be inherited from either a mother or father carrying an abnormal copy of the gene on their X chromosome. </p>
<p>Since the gene is on the X chromosome, a father cannot pass it on to his sons (fathers only pass on a Y chromosome to male offspring). </p>
<p>When the fragile X gene is passed on from a mother to her children, the gene may become altered to the point where it is unable to work properly. When this happens the gene cannot produce enough or any of the protein coded for it. </p>
<p>Although the exact function of this protein is not yet full understood, it is known to be critical to early intellectual and cognitive development. So the most prominent feature of fragile X is developmental difficulties.</p>
<h2>The autism-fragile X link</h2>
<p>One of the reasons why a diagnosis of fragile X is often delayed is because it shares many characteristics with autism. </p>
<p>Current research estimates that 25% to 35% of children who have fragile X are misdiagnosed as having autism due to the disorders’ many overlapping features. </p>
<p>Features common to both include language delay, echolalia, and repetitive speech alongside poor eye contact, and stereotypic movements such as hand biting and hand flapping. </p>
<p>Many children also display unusual reactions to environmental stimuli such as sudden noises e.g. sirens or alarms, movements, or changes such as a transition from one classroom activity to another. </p>
<p>The anxiety this provokes can often lead to hyper-arousal potentially leading to outbursts of aggression. </p>
<h2>Common behavioural challenges in people with fragile X</h2>
<p>Alongside hyperarousal, hypersensitivity is another early prominent behavioral feature in boys and girls with fragile X syndrome. </p>
<p>Children may become overwhelmed by the demands created by social involvement, novel or unexpected situations and changes, even the common transitions of daily life. </p>
<p>Another distinct and pervasive behavioral feature of the syndrome are attention and hyperactivity problems. </p>
<p>In the classroom, these behaviours can manifest themselves as difficulty in staying focused on a task for more than a few moments, difficulty in following very simple instructions, easy distraction by sudden noises or movements (e.g. scraping of a chair) and extreme impulsiveness. </p>
<p>The severity and prominence of these behaviours often contribute to a clinical diagnosis of Attention Deficit Hyperactivity Disorder (ADHD).</p>
<p>Another symptom is extreme shyness, which is experienced by many people with fragile X, especially girls, and can often hinder the desire to initiate friendships in childhood and adolescence.</p>
<h2>The importance of accurate diagnosis</h2>
<p>Misdiagnosis of children with fragile X denies them access to syndrome-specific resources and support systems. These would be most beneficial in early school years when intervention is most effective. </p>
<p>The physical features, social, behavioural and academic impairments present in people with fragile X differ from those with autism and ADHD so early intervention is doubly important.</p>
<p>Recognizing these features is critical to help clinicians properly diagnose the syndrome as early as possible in development so effective educational and clinical interventions can be implemented from a young age. </p>
<p>It is also important that resources are available for teachers from as early as preschool so that at every stage of academic transition, teachers and parents alike know what to expect and how to intervene with fragile X-specific educational resources. </p>
<p>The proposed development of “Building Links Australia” a virtual web resource for families, educators and clinicians will help create partnerships in understanding, intervening and treating children and adolescents with fragile X and other developmental disabilities across the academic trajectory. </p>
<h2>How the syndrome is detected</h2>
<p>A DNA test detecting fragile X syndrome with 99% accuracy was introduced in 1991. The test is routinely conducted on a blood sample. </p>
<p>It is important that when one family member receives the diagnosis, the rest of the family is also tested, so all carriers may have the chance to seek genetic counseling prior to bearing children. </p>
<p>In many families, there is no known history of fragile X and so the condition may go undetected until a sibling showing similar characteristics to his/her brother or sister is born. </p>
<p>Greater awareness of fragile X syndrome and how the disorder manifests across development is critical. This can only be achieved with better-targeted research and resources that ensure all Australians with fragile X are provided with opportunities to reach their full potential across their lifespan.</p>
<p>More information about fragile X can be obtained from the author and <a href="http://www.fragilex.org.au/">Fragile X Associaton of Australia</a>.</p><img src="https://counter.theconversation.com/content/298/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kim Cornish receives funding from the Australian Research Council. She is affiliated with Monash University and is a Board member of the Fragile X Associaton of Australia.
</span></em></p>Most people are not aware of fragile X syndrome but they may well be affected by it or know someone who is. Commonly under-diagnosed or misdiagnosed the condition is often mistaken for Attention Deficit…Kim Cornish, Head of School, School of Psychology & Psychiatry, Faculty of Medicine, Nursing and Health Sciences, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.