http://SaturnianCosmology.Org/ mirrored file For complete access to all the files of this collection see http://SaturnianCosmology.org/search.php ========================================================== Please participate in a vote to determine the future copyright terms of Wikimedia projects (vote ends May 3, 2009). Vote now! Scholarship applications for Wikimania 2009 are now open. Apply now! [Hide <#>] [Help us with translations! ] Influenza A virus subtype H3N2 From Wikipedia, the free encyclopedia Jump to: navigation <#column-one>, search <#searchInput> *Flu* * Influenza * Virus * Avian influenza * Swine influenza * Flu season * Research * Vaccine * Treatment * Genome project * H5N1 strain * H1N1 strain * Pandemic *H3N2* is a subtype of the influenza A virus . Its name derives from the forms of the two kinds of proteins on the surface of its coat, hemagglutinin (H) and neuraminidase (N). H3N2 viruses can infect birds and mammals. In birds, humans and pigs the virus has mutated into many strains. H3N2 exchanges genes for internal proteins with other influenza subtypes. The annual flu (also called "seasonal flu " or "human flu ") kills an estimated 36,000 people in the United States each year. Flu vaccines are based on predicting which mutants of H1N1 , H3N2, H1N2 , and influenza B will proliferate in the next season. Separate vaccines are developed for the northern and southern hemispheres in preparation for their annual epidemics. In the tropics, influenza shows no clear seasonality. In the past ten years, H3N2 has tended to dominate in prevalence over H1N1, H1N2, and influenza B. Measured resistance to the standard antiviral drugs amantadine and rimantadine in H3N2 has increased from 1% in 1994 to 12% in 2003 to 91% in 2005.^[1] <#cite_note-0> Contents [hide ] * 1 Seasonal H3N2 flu <#Seasonal_H3N2_flu> * 2 Swine flu <#Swine_flu> * 3 Hong Kong Flu (1968-1969) <#Hong_Kong_Flu_.281968-1969.29> * 4 Fujian flu (2003–2004) <#Fujian_flu_.282003.E2.80.932004.29> * 5 2004-2005 flu season <#2004-2005_flu_season> * 6 2005-2006 flu season <#2005-2006_flu_season> * 7 2006-2007 flu season <#2006-2007_flu_season> * 8 2007-2008 flu season <#2007-2008_flu_season> * 9 See also <#See_also> * 10 Further reading <#Further_reading> * 11 External links <#External_links> * 12 Sources <#Sources> [edit ] Seasonal H3N2 flu Seasonal H3N2 flu is a human flu from H3N2 that is slightly different from one of last year's flu season H3N2 variants. Seasonal influenza viruses flow out of overlapping epidemics in East and Southeast Asia , then trickle around the globe before dying off. Identifying the source of the viruses allows global health officials to better predict which viruses are most likely to cause the most disease over the next year. An analysis of 13,000 samples of influenza A/H3N2 virus that were collected across six continents from 2002 to 2007 by the WHO's Global Influenza Surveillance Network showed that newly emerging strains of H3N2 appeared in East and Southeast Asian countries about 6 to 9 months earlier than anywhere else. The strains generally reached Australia and New Zealand next, followed by North America and Europe. The new variants typically reached South America after an additional 6 to 9 months, the group reported.^[2] <#cite_note-1> [edit ] Swine flu Main article: Swine flu Pigs can harbor influenza viruses adapted to humans and others that are adapted to birds, allowing the viruses to exchange genes and create a pandemic strain. "In swine , 3 influenza A virus subtypes (H1N1 , H3N2, and H1N2 ) are circulating throughout the world. In the United States, the classic H1N1 subtype was exclusively prevalent among swine populations before 1998; however, since late August 1998, H3N2 subtypes have been isolated from pigs. Most H3N2 virus isolates are triple reassortants, containing genes from human (HA, NA, and PB1), swine (NS, NP, and M), and avian (PB2 and PA) lineages. [...] Present vaccination strategies for SIV control and prevention in swine farms typically include the use of 1 of several bivalent SIV vaccines commercially available in the United States. Of the 97 recent H3N2 isolates examined, only 41 isolates had strong serologic cross-reactions with antiserum to 3 commercial SIV vaccines. Since the protective ability of influenza vaccines depends primarily on the closeness of the match between the vaccine virus and the epidemic virus, the presence of nonreactive H3N2 SIV variants suggests that current commercial vaccines might not effectively protect pigs from infection with a majority of H3N2 viruses."^[3] <#cite_note-2> Avian influenza virus H3N2 is endemic in pigs in China and has been detected in pigs in Vietnam, increasing fears of the emergence of new variant strains. Health experts say pigs can carry human influenza viruses, which can combine (i.e. exchange homologous genome sub-units by genetic reassortment ) with H5N1 , passing genes and mutating into a form which can pass easily among humans. H3N2 evolved from H2N2 by antigenic shift and caused the Hong Kong Flu pandemic of 1968 and 1969 that killed up to 750,000 humans. The dominant strain of annual flu in humans in January 2006 is H3N2 . Measured resistance to the standard antiviral drugs amantadine and rimantadine in H3N2 in humans has increased to 91% in 2005. A combination of these two subtypes of the species known as the avian influenza virus in a country like China is a worst case scenario. In August 2004, researchers in China found H5N1 in pigs.^[4] <#cite_note-timeline-3> [edit ] Hong Kong Flu (1968-1969) It has been suggested that this section be split into a new article. (Discuss ) The *Hong Kong Flu* was a category 2 flu pandemic caused by a strain of H3N2 descended from H2N2 by antigenic shift , in which genes from multiple subtypes reassorted to form a new virus. This pandemic of 1968 and 1969 killed an estimated one million people worldwide.^[5] <#cite_note-4> ^[6] <#cite_note-5> ^[7] <#cite_note-6> The pandemic infected an estimated 500,000 Hong Kong residents, 15% of the population, with a low death rate.^[8] <#cite_note-Starling-7> In the United States, approximately 33,800 people died.^[9] <#cite_note-8> Both the H2N2 and H3N2 pandemic flu strains contained genes from avian influenza viruses. The new subtypes arose in pigs coinfected with avian and human viruses and were soon transferred to humans. Swine were considered the original "intermediate host" for influenza, because they supported reassortment of divergent subtypes. However, other hosts appear capable of similar coinfection (e.g., many poultry species), and direct transmission of avian viruses to humans is possible. H1N1 may have been transmitted directly from birds to humans (Belshe 2005).^[10] <#cite_note-9> The Hong Kong flu strain shared internal genes and the neuraminidase with the 1957 Asian Flu (H2N2 ). Accumulated antibodies to the neuraminidase or internal proteins may have resulted in much fewer casualties than most pandemics . However, cross-immunity within and between subtypes of influenza is poorly understood. The Hong Kong flu was the first known outbreak of the H3N2 strain, though there is serologic evidence of H3N? infections in the late 19th century. The first record of the outbreak in Hong Kong appeared on 13 July 1968 in an area with a density of about 500 people per acre in an urban setting. The outbreak reached maximum intensity in 2 weeks, lasting 6 weeks in total. The virus was isolated in Queen Mary Hospital . Flu symptoms lasted 4 to 5 days.^[8] <#cite_note-Starling-7> By July 1968, extensive outbreaks were reported in Vietnam and Singapore . By September 1968, it would reach India , Philippines , northern Australia and Europe. That same month, the virus entered California from returning Vietnam War troops . It would reach Japan , Africa and South America by 1969.^[8] <#cite_note-Starling-7> "Three strains of Hong Kong influenza virus isolated from humans were compared with a strain isolated from a calf for their ability to cause disease in calves. One of the human strains. A/Aichi/2/68, was detected for five days in a calf, but all three failed to cause signs of disease. Strain A/cal/Duschanbe/55/71 could be detected for seven days and caused an influenza-like illness in calves."^[11] <#cite_note-10> [edit ] Fujian flu (2003–2004) Main article: Fujian flu Diagram of influenza virus nomenclature . Fujian flu refers to flu caused by either a Fujian human flu strain of the H3N2 subtype of the /Influenza A virus / or a Fujian bird flu strain of the H5N1 subtype of the /Influenza A virus/. These strains are named after Fujian , a coastal province of the People's Republic of China that is across the Taiwan strait from Taiwan .^[12] <#cite_note-11> A/Fujian (H3N2) human flu (from A/Fujian/411/2002(H3N2) -like flu virus strains) caused an unusually severe 2003–2004 flu season. This was due to a reassortment event that caused a minor clade to provide a haemagglutinin gene that later became part of the dominant strain in the 2002–2003 flu season. A/Fujian (H3N2) was made part of the trivalent influenza vaccine for the 2004-2005 flu season and its descendants are still the most common human H3N2 strain. [edit ] 2004-2005 flu season The 2004–05 trivalent influenza vaccine for the United States contained A/New Caledonia/20/99-like (H1N1), A/Fujian/411/2002-like (H3N2) , and B/Shanghai/361/2002-like viruses.^[13] <#cite_note-CDC_2003_to_2005-12> [edit ] 2005-2006 flu season The vaccines produced for the 2005–2006 season use: * an A/New Caledonia/20/1999-like(H1N1 ); * an A/California/7/2004-like(H3N2 ) (or the antigenically equivalent strain A/New York/55/2004); * a B/Jiangsu/10/2003-like viruses. [edit ] 2006-2007 flu season The 2006–2007 influenza vaccine composition recommended by the World Health Organization on 15 February 2006 and the U.S. FDA's Vaccines and Related Biological Products Advisory Committee (VRBPAC) on 17 February 2006 use: * an A/New Caledonia/20/99 (H1N1)-like virus; * an A/Wisconsin/67/2005 (H3N2)-like virus (A/Wisconsin/67/2005 and A/Hiroshima/52/2005 strains); * a B/Malaysia/2506/2004-like virus from B/Malaysia/2506/2004 and B/Ohio/1/2005 strains which are of B/Victoria/2/87 lineage.^[14] <#cite_note-13> [edit ] 2007-2008 flu season The composition of influenza virus vaccines for use in the 2007–2008 Northern Hemisphere influenza season recommended by the World Health Organization on 14 February 2007^[15] <#cite_note-14> was: * an A/Solomon Islands/3/2006 (H1N1)-like virus; * an A/Wisconsin/67/2005 (H3N2)-like virus (A/Wisconsin/67/2005 (H3N2) and A/Hiroshima/52/2005 were used at the time); * a B/Malaysia/2506/2004-like virus^[16] <#cite_note-15> ^[17] <#cite_note-16> "A/H3N2 has become the predominant flu subtype in the United States, and the record over the past 25 years shows that seasons dominated by H3N2 tend to be worse than those dominated by type A/H1N1 or type B." Many H3N2 viruses making people ill in this 2007-2008 flu season differ from the strains in the vaccine and may not be well covered by the vaccine strains. "The CDC has analyzed 250 viruses this season to determine how well they match up with the vaccine, the report says. Of 65 H3N2 isolates, 53 (81%) were characterized as A/Brisbane/10/2007-like, a variant that has evolved [notably] from the H3N2 strain in the vaccine—A/Wisconsin/67/2005."^[18] <#cite_note-17> [edit ] See also * 2009 H1N1 influenza outbreak * Bird flu * Dog flu * Horse flu * Human flu * Swine flu [edit ] Further reading * Graphic showing H3N2 mutations, amino acid by amino acid, among 207 isolates completely sequenced by the Influenza Genome Sequencing Project . * Influenza A (H3N2) Outbreak, Nepal * Hot topic - Fujian-like strain A influenza * Monitoring Antibodies for Swine Influenza H3N2 Virus * Human influenza A(H3N2) activity remains widespread in many countries - update 7 * Human influenza A/H3N2 activity increases in many countries in central and eastern Europe - update 8 * Influenza A H3N2 * New Scientist: Bird Flu [edit ] External links * BioHealthBase Bioinformatics Resource Center Database of influenza sequences and related information. [edit ] Sources 1. *^ <#cite_ref-0>* Reason New York Times 2. *^ <#cite_ref-1>* CIDRAP article /Study: New seasonal flu strains launch from Asia/ published 16 April 2008 3. *^ <#cite_ref-2>* pubmedcentral.nih.gov Canadian Journal of Veterinary Research (2007 July; 71(3): 201–206.) article /Serologic and genetic characterization of North American H3N2 swine influenza A viruses/ by Marie René Gramer, Jee Hoon Lee, Young Ki Choi, Sagar M. Goyal, and Han Soo Joo 4. *^ <#cite_ref-timeline_3-0>* WHO (28 October 2005). "H5N1 avian influenza: timeline" (PDF). http://www.who.int/csr/disease/avian_influenza/Timeline_28_10a.pdf. 5. *^ <#cite_ref-4>* Paul, William E.. /Fundamental Immunology /. pp. 1273. http://books.google.com/books?id=oPSG1PGmZUkC. 6. *^ <#cite_ref-5>* "World health group issues alert Mexican president tries to isolate those with swine flu" . Associated Press. April 25, 2009. http://www.jsonline.com/news/usandworld/43705182.html. Retrieved on 2009-04-26. 7. *^ <#cite_ref-6>* Mandel, Michael (April 26, 2009). "No need to panic ... yet Ontario officials are worried swine flu could be pandemic, killing thousands" . Toronto Sun. http://www.torontosun.com/news/2009/04/26/9248411-sun.html. Retrieved on 2009-04-26. 8. ^ ^/*a*/ <#cite_ref-Starling_7-0> ^/*b*/ <#cite_ref-Starling_7-1> ^/*c*/ <#cite_ref-Starling_7-2> Starling, Arthur (2006). /Plague, SARS, and the Story of Medicine in Hong Kong /. HK University Press. p. 55. ISBN 9622098053 . http://books.google.com/books?id=WBx6McA35iYC. 9. *^ <#cite_ref-8>* U.S. Department of Health and Human Services, http://www.pandemicflu.gov/general/historicaloverview.html 10. *^ <#cite_ref-9>* Chapter Two : Avian Influenza by Timm C. Harder and Ortrud Werner from excellent free on-line Book called /Influenza Report 2006/ which is a medical textbook that provides a comprehensive overview of epidemic and pandemic influenza. 11. *^ <#cite_ref-10>* J Infect Dis. 1977 Apr;135(4):678-80. article /Strains of Hong Kong influenza virus in calves/ 12. *^ <#cite_ref-11>* Fujian also borders the north of China's Guangdong province, where Hong Kong is. Hong Kong is important in the early history of H5N1 . 13. *^ <#cite_ref-CDC_2003_to_2005_12-0>* CDC article /Update: Influenza Activity — United States and Worldwide, 2003–04 Season, and Composition of the 2004–05 Influenza Vaccine/ published 2 July 2004 14. *^ <#cite_ref-13>* CDC fluwatch B/Victoria/2/87 lineage 15. *^ <#cite_ref-14>* 14 February 2007: WHO information meeting (Morning) 16. *^ <#cite_ref-15>* WHO website recommendation for 2007-2008 season 17. *^ <#cite_ref-16>* WHO — Recommended composition of influenza virus vaccines for use in the 2007-2008 influenza season (PDF) 18. *^ <#cite_ref-17>* CIDRAP article /Flu widespread in 44 states, CDC reports/ published 15 February 2008 [hide ] v • d • e Influenza General topics Research - Vaccine - Treatment - Genome sequencing - Reassortment - Superinfection - Season Influenza viruses Orthomyxoviridae - Influenza A - Influenza B - Influenza C Influenza A virus Subtypes H1N1 - H1N2 - H2N2 - H2N3 - H3N1 - *H3N2* - H3N8 - H5N1 - H5N2 - H5N3 - H5N8 - H5N9 - H7N1 - H7N2 - H7N3 - H7N4 - H7N7 - H9N2 - H10N7 H1N1 Pandemics 1918 flu pandemic - Russian Flu - 2009 swine flu outbreak Outbreaks Mexico - United States - Canada - United Kingdom - Spain - New Zealand - Israel H5N1 Science Genetic structure - Transmission and infection - Global spread - Clinical Trials - Human mortality Outbreaks Croatia (2005) - India (2006) - UK (2007) - West Bengal (2008) Treatments Antiviral drugs Arbidol - /adamantane derivatives / (Amantadine , Rimantadine ) - /neuraminidase inhibitors / (Oseltamivir , Peramivir , Zanamivir ) /Experimental/ (Peramivir ) Vaccines FluMist - Fluzone Influenza epidemics Pandemics 1918 flu - Asian Flu - Hong Kong Flu - Fujian flu - Pandemic Severity Index Epidemics Epidemics - 2007 Australian outbreak - 2009 swine flu outbreak Non-human Mammals Canine influenza - Equine influenza (2007 Australian outbreak ) - Swine influenza Non-mammals Avian influenza Retrieved from "http://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H3N2" Categories : Health in Hong Kong | Subtypes of Influenza A virus Hidden categories: Wikipedia articles to be split from April 2009 Views * Article * Discussion * Edit this page * History Personal tools * Log in / create account Navigation * Main page * Contents * Featured content * Current events * Random article Search Interaction * About Wikipedia * Community portal * Recent changes * Contact Wikipedia * Donate to Wikipedia * Help Toolbox * What links here * Related changes * Upload file * Special pages * Printable version * Permanent link * Cite this page Languages * Deutsch * Español * Français * Italiano * Nederlands * 日本語 * Português * Svenska * 中文 Powered by MediaWiki Wikimedia Foundation * This page was last modified on 28 April 2009, at 04:58 (UTC). * All text is available under the terms of the GNU Free Documentation License . 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