{"id":1243,"date":"2018-06-22T17:03:27","date_gmt":"2018-06-22T11:33:27","guid":{"rendered":"https:\/\/triumphias.com\/blog\/?p=1243"},"modified":"2018-06-22T17:03:27","modified_gmt":"2018-06-22T11:33:27","slug":"influenza-virus","status":"publish","type":"post","link":"https:\/\/triumphias.com\/blog\/influenza-virus\/","title":{"rendered":"Influenza virus"},"content":{"rendered":"<p><strong>Influenza<\/strong><\/p>\n<ul>\n<li>Influenza is a virus that actually has hundreds of different strains. The virus mutates frequently, but the strains are classified into one of three main categories\u2014A, B, or C.<\/li>\n<li>The virus can be transmitted by direct contact with infected individuals, via contaminated objects (also called fomites) and by inhalation of virus-laden aerosols.<\/li>\n<li>An unexpected emergence of a new and highly virulent influenza virus strains can result in a world-wide pandemics with high morbidity and mortality \u2013 such as the \u201cavian flu\u201d in 1997 and \u201cswine flu\u201d in 2009.<\/li>\n<li>Human influenza viruses are single-stranded RNA viruses. The main targets of the virus are the columnar epithelial cells of the respiratory tract, i.e. trachea, bronchi and bronchioles.<\/li>\n<li>Infectivity of influenza virus particles depends on the pH, temperature and salinity of the water, as well as the UV irradiation.<\/li>\n<\/ul>\n<p><a href=\"https:\/\/triumphias.com\/blog\/wp-content\/uploads\/2018\/06\/influenza.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1249\" src=\"https:\/\/triumphias.com\/blog\/wp-content\/uploads\/2018\/06\/influenza.jpg\" alt=\"\" width=\"500\" height=\"388\" srcset=\"https:\/\/triumphias.com\/blog\/wp-content\/uploads\/2018\/06\/influenza.jpg 500w, https:\/\/triumphias.com\/blog\/wp-content\/uploads\/2018\/06\/influenza-150x116.jpg 150w, https:\/\/triumphias.com\/blog\/wp-content\/uploads\/2018\/06\/influenza-300x233.jpg 300w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><\/a><\/p>\n<p><strong>Influenza types<\/strong><\/p>\n<ul>\n<li>Influenza is caused by three types of RNA viruses called influenza types A, B and C (considered different genera), which all belong to the family Orthomyxoviridae.<\/li>\n<li>The disease, colloquially called &#8220;flu&#8221; in humans, is generally caused by the viruses A and B.<\/li>\n<li>Subtypes of influenza A and B viruses can be further characterized into strains. There is a plethora of different strains of influenza B viruses and of influenza A subtypes, and new strains of influenza viruses can appear and replace older strains.<\/li>\n<li>Influenza type A viruses are known to infect people, birds, pigs, horses, whales, seals and other animals, but wild birds represent the natural hosts for these viruses.<\/li>\n<li>Only a fraction influenza A subtypes (i.e. H1N1, H1N2 and H3N2) are currently in general circulation among people.<\/li>\n<li>Influenza B viruses are responsible the same spectrum of disease as influenza A. And, influenza B viruses do not cause pandemics.<\/li>\n<li>Influenza C viruses are different in comparison to influenza A and B. They cause a mild respiratory illness and are not thought to cause epidemics.<\/li>\n<\/ul>\n<p><strong><em>Influenza A<\/em><\/strong><\/p>\n<ul>\n<li>Influenza A is the group that most commonly causes illness in humans.<\/li>\n<li>All influenza A viruses are further broken down into H and N subtypes. So, any influenza virus that is described as \u201cH#N#\u201d (such as H1N1) is influenza A virus.<\/li>\n<li>There are 16 H subtypes and nine N subtypes, but only three combinations have actually caused highly contagious illness in humans.<\/li>\n<li>Other combinations have been found to infect other species (such as birds and pigs), but they have not caused widespread human infections.<\/li>\n<li>The three combinations that cause almost all outbreaks of the flu in humans are H1N1, H2N2 and H3N2.<\/li>\n<li>Even in these subtypes, the influenza virus can mutate and change each year. For this reason, influenza viruses are also named using:<\/li>\n<li>The host of origin (swine, chicken, etc., or no host if it is of human origin)<\/li>\n<li>The geographical location of origin (Hong Kong, Alberta, etc.)<\/li>\n<li>Strain number<\/li>\n<li>Year of discovery (or isolation)<\/li>\n<\/ul>\n<p><strong><em>Influenza B<\/em><\/strong><\/p>\n<ul>\n<li>Influenza B is less common but still causes outbreaks of seasonal flu.<\/li>\n<li>One or two strains of influenza B are included in the seasonal flu vaccine every year to protect people from the strain(s) that researchers believe are most likely to cause illness during the upcoming flu season.<\/li>\n<li>The quadrivalent flu vaccine contains two strains of influenza B but the traditional trivalent flu vaccine only contains one.<\/li>\n<li>Influenza B is not broken down into subtypes like influenza A is, but it is broken down into individual strains.<\/li>\n<li>Typically, two strains of influenza A and one strain of influenza B are included in the seasonal flu vaccine. Quadrivalent flu vaccines contain two strains of influenza A and two strains of influenza B.<\/li>\n<li>Influenza B can cause outbreaks of seasonal flu but they occur less frequently than outbreaks of influenza A.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Influenza Influenza is a virus that actually has hundreds of different strains. The virus mutates frequently, but the strains are<\/p>\n","protected":false},"author":1,"featured_media":882,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[123],"tags":[136,291,650,649],"class_list":["post-1243","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-current-affairs","tag-current-affairs","tag-daily-current-affairs","tag-influenza","tag-influenza-virus"],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/triumphias.com\/blog\/wp-json\/wp\/v2\/posts\/1243","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/triumphias.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/triumphias.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/triumphias.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/triumphias.com\/blog\/wp-json\/wp\/v2\/comments?post=1243"}],"version-history":[{"count":1,"href":"https:\/\/triumphias.com\/blog\/wp-json\/wp\/v2\/posts\/1243\/revisions"}],"predecessor-version":[{"id":1251,"href":"https:\/\/triumphias.com\/blog\/wp-json\/wp\/v2\/posts\/1243\/revisions\/1251"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/triumphias.com\/blog\/wp-json\/wp\/v2\/media\/882"}],"wp:attachment":[{"href":"https:\/\/triumphias.com\/blog\/wp-json\/wp\/v2\/media?parent=1243"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/triumphias.com\/blog\/wp-json\/wp\/v2\/categories?post=1243"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/triumphias.com\/blog\/wp-json\/wp\/v2\/tags?post=1243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}