{"id":2621,"date":"2020-10-02T11:33:00","date_gmt":"2020-10-02T03:33:00","guid":{"rendered":"https:\/\/www.mdis.edu.sg\/blog\/?p=2621"},"modified":"2020-10-23T11:55:42","modified_gmt":"2020-10-23T03:55:42","slug":"hepatitis-a","status":"publish","type":"post","link":"https:\/\/www.mdis.edu.sg\/blog\/hepatitis-a\/","title":{"rendered":"Hepatitis A"},"content":{"rendered":"\n<p>The\nliver is one of the most important organs in the human body and plays a vital\nrole in metabolism, excretion, digestion, osmoregulation, detoxification and\nmore. The condition of inflammation of the liver is known as hepatitis.\nHepatitis can be caused by excessive alcohol intake, medications and autoimmune\nreactions. However, the most common cause is viral infection. <\/p>\n\n\n\n<figure class=\"wp-block-gallery columns-1 is-cropped\"><ul class=\"blocks-gallery-grid\"><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" width=\"960\" height=\"720\" src=\"https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/HAV.jpg\" alt=\"\" data-id=\"2624\" data-full-url=\"https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/HAV.jpg\" data-link=\"https:\/\/www.mdis.edu.sg\/blog\/?attachment_id=2624\" class=\"wp-image-2624\" srcset=\"https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/HAV.jpg 960w, https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/HAV-300x225.jpg 300w, https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/HAV-768x576.jpg 768w, https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/HAV-400x300.jpg 400w, https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/HAV-800x600.jpg 800w\" sizes=\"(max-width: 960px) 100vw, 960px\" \/><\/figure><\/li><\/ul><\/figure>\n\n\n\n<p>Hepatitis\nA, B, C, D and E are the presently known types. Of these, the Hepatitis caused\nby the Hepatitis A Virus (HAV) is also known as infectious hepatitis or epidemic\njaundice. It is an infectious disease which spreads mainly through the faecal-oral\nroute, therefore, when a healthy individual ingests water or food contaminated\nwith the faeces of an infected person. In rare cases, it is spread through\nclose contact between family members and blood transfusion. High prevalence of\nHAV can be seen in regions with poor sanitation, household crowding and\ninadequate supply of clean drinking water. <\/p>\n\n\n\n<figure class=\"wp-block-gallery columns-1 is-cropped\"><ul class=\"blocks-gallery-grid\"><li class=\"blocks-gallery-item\"><figure><img loading=\"lazy\" width=\"1024\" height=\"397\" src=\"https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/Hep-A-distribution-1024x397.jpg\" alt=\"\" data-id=\"2625\" data-full-url=\"https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/Hep-A-distribution.jpg\" data-link=\"https:\/\/www.mdis.edu.sg\/blog\/?attachment_id=2625\" class=\"wp-image-2625\" srcset=\"https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/Hep-A-distribution-1024x397.jpg 1024w, https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/Hep-A-distribution-300x116.jpg 300w, https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/Hep-A-distribution-768x298.jpg 768w, https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/Hep-A-distribution-400x155.jpg 400w, https:\/\/www.mdis.edu.sg\/blog\/wp-content\/uploads\/2020\/10\/Hep-A-distribution.jpg 1076w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/li><\/ul><\/figure>\n\n\n\n<p>Globally,\nalmost 1.5 million cases of hepatitis A are reported each year but this number\nonly reveals a part of the picture. Since almost 50% of the affected children\nbelow six years of age are asymptomatic and the rest have mild symptoms, which\nare often not regarded as hepatitis, the actual number of cases could be ten\ntimes the numbers reported (Franco et al., 2012). The <a>HAV<\/a><a href=\"#_msocom_1\">[SS1]<\/a>&nbsp;\nis a non-enveloped virus which carries its genetic material as single stranded Ribonucleic\nacid (<a>RNA<\/a><a href=\"#_msocom_2\">[SS2]<\/a>&nbsp;<a href=\"#_msocom_3\">[73]<\/a>&nbsp;<a href=\"#_msocom_4\">[74]<\/a>&nbsp;).\nIn 1991, it was classified as a member of the Hepatovirus genus of the Picornaviridae family. Studies on\ndifferent HAV strains from around the world show that only a single serotype of\nthe virus exists (Cuthbert, 2001).&nbsp; <\/p>\n\n\n\n<p>Once\ninside the human body, the HAV enters the liver cells and replicates. The\nreplication leads to a disruption of normal liver functions, an immune response\ninitiation and subsequent inflammation. The incubation period is 2-6 weeks long,\nduring which, the shedding of infectious viral particles in the faeces\nincreases. This shedding reaches its peak at the onset of symptoms and\ngradually declines then. The initial symptoms seen can include malaise,\nfatigue, fever, nausea and vomiting, which can later develop into jaundice,\ndark cola-coloured urine and clay-coloured stools (Lemon, 1997). <\/p>\n\n\n\n<p>The\nacute liver infection may last from two to six months and rarely develops into\nchronic infection. The severity of disease and the chances of a fatal outcome\nincreases with age. Increasing levels of <a>ALT, AST <\/a><a href=\"#_msocom_5\">[SS5]<\/a>&nbsp;and\nbilirubin indicates the presence of hepatic injury and can be used for a\npreliminary diagnosis. ALT and AST are the enzymes which are released by liver\ncells in response to cellular damage.<\/p>\n\n\n\n<p>In\nresponse to the HAV, virus-specific <a>IgM<\/a><a href=\"#_msocom_6\">[SS6]<\/a>&nbsp;\nantibodies are made and the detection of this acute-phase antibody response\nusing <a>ELISA<\/a><a href=\"#_msocom_7\">[SS7]<\/a>&nbsp;\nis the central focus of diagnosis. There is no specific treatment available for\nHepatitis A and recovery from symptoms is the main aim of therapy. <\/p>\n\n\n\n<p>In\ncases such as epidemic jaundice, the importance of prevention increases. Since\n1992, safe and effective Formalin-killed whole virus vaccines have been\ndeveloped to help countries control community-wide outbreaks. As of 2019, 34\ncountries used or are planning to introduce the vaccine against Hepatitis A in\ntheir immunisation routine (Hepatitis A, 2020.). <\/p>\n\n\n\n<p>Children\nin high risk regions and travellers going to such regions should be immunised.\nOther than immunisation, some simple measures can help to bring the spread of\nthe virus under control. Improvement in living standards, proper disposal of\nsewage, better access to clean drinking water combined with greater personal\nhygiene can help immensely. 28 July is celebrated world-wide as the World Hepatitis\nDay with the aim to increase awareness among people and educate them to better\nprevent future outbreaks.<\/p>\n\n\n\n<p>References:<\/p>\n\n\n\n<p>Franco, E., Meleleo, C., Serino, L., Sorbara, D.,\n&amp; Zaratti, L. (2012). Hepatitis A: Epidemiology and prevention in\ndeveloping countries. World Journal of Hepatology, 4(3), 68\u201373. <\/p>\n\n\n\n<p>Lemon, S. M. (1997). Type A viral hepatitis:\nepidemiology, diagnosis, and prevention. Clinical Chemistry, 43(8), 1494\u20131499. <\/p>\n\n\n\n<p>Hepatitis A. (2020). Retrieved August 19, 2020, from <a href=\"https:\/\/www.who.int\/news-room\/fact-sheets\/detail\/hepatitis-a\">https:\/\/www.who.int\/news-room\/fact-sheets\/detail\/hepatitis-a<\/a><\/p>\n\n\n\n<p>Cuthbert, J. A. (2001). Hepatitis A: Old and New.\nClinical Microbiology Reviews, 14(1), 38\u201358. <\/p>\n\n\n\n<p>Pictures:<\/p>\n\n\n\n<p>Hepatitis A distribution: Lemon, S. M., Ott, J. J., Damme, P. V., &amp; Shouval,\nD. (2018). Type A viral hepatitis: A summary and update on the molecular\nvirology, epidemiology, pathogenesis and prevention. Journal of Hepatology,\n68(1), 167\u2013184. <\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p>This article is contributed by Nazuk Gupta from the <a aria-label=\"School of Life Sciences (opens in a new tab)\" href=\"https:\/\/www.mdis.edu.sg\/school-of-life-sciences\" target=\"_blank\" rel=\"noreferrer noopener\" class=\"rank-math-link\">School of Life Sciences<\/a> pursuing a <a href=\"https:\/\/www.mdis.edu.sg\/bachelor-of-science-hons-biotechnology\" target=\"_blank\" aria-label=\"bachelors of Science in Biotechnology (opens in a new tab)\" rel=\"noreferrer noopener\" class=\"rank-math-link\">bachelors of Science in Biotechnology<\/a> with honours awarded by <a href=\"https:\/\/www.mdis.edu.sg\/northumbria-university-newcastle\" target=\"_blank\" aria-label=\"Northumbria University (opens in a new tab)\" rel=\"noreferrer noopener\" class=\"rank-math-link\">Northumbria University<\/a>.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The liver is one of the most important organs in the human body and plays a vital role in metabolism, excretion, digestion, osmoregulation, detoxification and more. The condition of inflammation of the liver is known as hepatitis. Hepatitis can be caused by excessive alcohol intake, medications and autoimmune reactions. However, the most common cause is viral infection. Hepatitis A, B, C, D and E are the presently known types. Of these, the Hepatitis caused by the Hepatitis A Virus (HAV) is also known as infectious hepatitis or epidemic jaundice. It is an infectious disease which spreads mainly through the faecal-oral [&hellip;]<\/p>\n","protected":false},"author":298,"featured_media":2623,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[27,13],"tags":[],"_links":{"self":[{"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/posts\/2621"}],"collection":[{"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/users\/298"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/comments?post=2621"}],"version-history":[{"count":1,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/posts\/2621\/revisions"}],"predecessor-version":[{"id":2626,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/posts\/2621\/revisions\/2626"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/media\/2623"}],"wp:attachment":[{"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/media?parent=2621"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/categories?post=2621"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/tags?post=2621"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}