Búsqueda personalizada

Influenza A virus subtype H1N1

For the 1918 pandemic of Influenza A(H1N1), see 1918 flu pandemic.
For the current pandemic of Influenza A(H1N1), see 2009 flu pandemic.
Avian influenza
Swine influenza
Flu season
A/H5N1 subtype
A/H1N1 subtype
"Dr. Mary Young, assistant professor of medicine at Georgetown University Medical Center, discusses Influenza A H1N1 (swine flu), its symptoms, and steps that can be taken to prevent contracting"

Influenza A virus subtype H1N1, also known as A(H1N1), is a subtype of influenzavirus A and the most common cause of influenza (flu) in humans. Some strains of H1N1 are endemic in humans and cause a small fraction of all influenza-like illness and a large fraction of all seasonal influenza. H1N1 strains caused roughly half of all human flu infections in 2006. Other strains of H1N1 are endemic in pigs (swine influenza) and in birds (avian influenza).

In June 2009, WHO declared that flu due to a new strain of swine-origin H1N1 was responsible for the 2009 flu pandemic. This strain is commonly called "swine flu".

1 Nomenclature
2 Spanish flu
3 Russian flu
4 2009 Influenza A(H1N1) pandemic
5 See also
6 Notes
7 External links
7.1 Nontechnical
7.2 Technical


The various types of influenza viruses in humans. Solid squares show the appearance of a new strain, causing recurring influenza pandemics. Broken lines indicate uncertain strain identifications. Influenza A virus strains are categorized according to two proteins found on the surface of the virus: hemagglutinin (H) and neuraminidase (N). All influenza A viruses contain hemagglutinin and neuraminidase, but the structure of these proteins differ from strain to strain due to rapid genetic mutation in the viral genome.

Influenza A virus strains are assigned an H number and an N number based on which forms of these two proteins the strain contains. There are 16 H and 9 N subtypes known in birds, but only H 1, 2 and 3, and N 1 and 2 are commonly found in humans.

Spanish flu
Main article: 1918 flu pandemic
The Spanish flu, also known as La Gripe Española, or La Pesadilla, was an unusually severe and deadly strain of avian influenza, a viral infectious disease, that killed some 50 million to 100 million people worldwide over about a year in 1918 and 1919. It is thought to be one of the most deadly pandemics in human history. It was caused by the H1N1 type of influenza virus.

The Spanish flu caused an unusual number of deaths because it may have caused a cytokine storm in the body. (The recent epidemic of bird flu, also an Influenza A virus, had a similar effect.)The Spanish flu virus infected lung cells, leading to overstimulation of the immune system via release of cytokines into the lung tissue. This leads to extensive leukocyte migration towards the lungs, causing destruction of lung tissue and secretion of liquid into the organ. This makes it difficult for the patient to breathe. In contrast to other pandemics, which mostly kill the old and the very young, the 1918 pandemic killed unusual numbers of young adults, which may have been due to their healthy immune systems being able to mount a very strong and damaging response to the infection.

The term "Spanish" flu was coined because Spain was at the time the only European country where the press were printing reports of the outbreak, which had killed thousands in the armies fighting the First World War. Other countries suppressed the news in order to protect morale.

Russian flu
See Influenza A virus subtype H2N2#Russian flu for the 1889–1890 Russian flu
The more recent Russian flu was a 1977–1978 flu epidemic caused by strain Influenza A/USSR/90/77 (H1N1). It infected mostly children and young adults under 23 because a similar strain was prevalent in 1947–57, causing most adults to have substantial immunity. Some have called it a flu pandemic but because it only affected the young it is not considered a true pandemic. The virus was included in the 1978–1979 influenza vaccine.

2009 Influenza A(H1N1) pandemic

Illustration of influenza antigenic shift.Main article: 2009 flu pandemic
In the 2009 flu pandemic, the virus isolated from patients in the United States was found to be made up of genetic elements from four different flu viruses – North American Mexican influenza, North American avian influenza, human influenza, and swine influenza virus typically found in Asia and Europe – "an unusually mongrelised mix of genetic sequences." This new strain appears to be a result of reassortment of human influenza and swine influenza viruses, in all four different strains of subtype H1N1.

Preliminary genetic characterization found that the hemagglutinin (HA) gene was similar to that of swine flu viruses present in U.S. pigs since 1999, but the neuraminidase (NA) and matrix protein (M) genes resembled versions present in European swine flu isolates. The six genes from American swine flu are themselves mixtures of swine flu, bird flu, and human flu viruses. While viruses with this genetic makeup had not previously been found to be circulating in humans or pigs, there is no formal national surveillance system to determine what viruses are circulating in pigs in the U.S.

On June 11, 2009, the WHO declared an H1N1 pandemic, moving the alert level to phase 6, marking the first global pandemic since 1968.

See also
Fujian flu
2009 A/H1N1

^ "CDC". http://www.cdc.gov/flu/weekly/.
^ a b Palese P (December 2004). "Influenza: old and new threats". Nat. Med. 10 (12 Suppl): S82–7. doi:10.1038/nm1141. PMID 15577936.
^ Lynch JP, Walsh EE (April 2007). "Influenza: evolving strategies in treatment and prevention". Semin Respir Crit Care Med 28 (2): 144–58. doi:10.1055/s-2007-976487. PMID 17458769.
^ http://www.fas.org/programs/ssp/bio/factsheets/H1N1factsheet.html
^ Kobasa D, Jones SM, Shinya K, et al (January 2007). "Aberrant innate immune response in lethal infection of macaques with the 1918 influenza virus". Nature 445 (7125): 319–23. doi:10.1038/nature05495. PMID 17230189.
^ Kash JC, Tumpey TM, Proll SC, et al (October 2006). "Genomic analysis of increased host immune and cell death responses induced by 1918 influenza virus". Nature 443 (7111): 578–81. doi:10.1038/nature05181. PMID 17006449. PMC: 2615558. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17006449.
^ Cheung CY, Poon LL, Lau AS, et al (December 2002). "Induction of proinflammatory cytokines in human macrophages by influenza A (H5N1) viruses: a mechanism for the unusual severity of human disease?". Lancet 360 (9348): 1831–7. PMID 12480361.
^ Barry, John M. (2004). The Great Influenza: The Epic Story of the Greatest Plague in History. Viking Penguin. ISBN 0-670-89473-7.
^ CNN interactive health timeline box 1977: Russian flu scare
^ Time magazine article Invasion from the Steppes published February 20, 1978
^ Global Security article Pandemic Influenza subsection Recent Pandemic Flu Scares
^ State of Alaska Epidemiology Bulletin Bulletin No. 9 - April 21, 1978 - Russian flu confirmed in Alaska
^ "Deadly new flu virus in US and Mexico may go pandemic". New Scientist. 2009-04-26. http://www.newscientist.com/article/dn17025-deadly-new-flu-virus-in-us-and-mexico-may-go-pandemic.html. Retrieved on 2009-04-26.
^ Susan Watts (2009-04-25). "Experts concerned about potential flu pandemic". BBC. http://www.bbc.co.uk/blogs/newsnight/susanwatts/2009/04/experts_concerned_about_potent.html.
^ "Swine Influenza A (H1N1) Infection in Two Children --- Southern California, March--April 2009". CDC MMWR. 2009-04-22. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5815a5.htm.
^ Blippitt (2009-06-11). "H1N1 Pandemic - It's Official". N/A. http://www.blippitt.com/h1n1-pandemic-official.

External links
BioHealthBase Bioinformatics Resource Center Database of influenza genomic sequences and related information.
American Medical Association Physician Resources: Swine Flu
Consultant Magazine H1N1 (Swine Flu) Center
Wikinews has related news: Swine flu cases worldwide top 1,000
Pandemic Influenza: A Guide to Recent Institute of Medicine Studies and Workshops A collection of research papers and summaries of workshops by the Institute of Medicine on major policy issues related to pandemic influenza and other infectious disease threats.
The Swine Flu Affair: Decision-Making on a Slippery Disease Report commissioned by the Department of Health, Education and Welfare, written by Richard Neustadt and Harvey V. Fineberg. An examination of what happened during and after the 1976 swine flu outbreak and lessons to help cope with similar situations in the future.
Pandemik Global Map Dynamics maps, graphics and statistics about the A/H1N1 virus.
Pandemic Preparedness Guide Pandemic Preparedness information for Individuals, families or business: Swine Flu or Bird Flu.

Why Revive a Deadly Flu Virus? By Jamie Shreeve - January 2006 New York Times - Six-page human-interest story on the recreation of the deadly 1918 H1N1 flu virus
BBC News - 1918 flu virus's secrets revealed Results from analyzing a recreated strain.
Publicly available data
Oral history by 1918 pandemic survivor
Public Flu Forum

Recent influenza A (H1N1) infections of pigs and turkeys in northern Europe
Epidemiologic Notes and Reports Influenza A(H1N1) Associated With Mild Illness in a Nursing Home -- Maine
Swine Influenza Vaccine, H1N1 & H3N2, Killed Virus
Influenza Virus Infections of Pigs
H1N1-influenza as Lazarus: Genomic resurrection from the tomb of an unknown
v • d • eInfluenza

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 (Spanish flu) - 2009 flu pandemic

Science 2009 A/H1N1

H5N1 Science Genetic structure - Transmission and infection - Global spread - Clinical Trials - Human mortality - Social impact - Pandemic preparation

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)

Flu vaccines FluMist - Fluzone

Influenza epidemics & pandemics Pandemics Russian flu (1889–1890) - Spanish Flu - Asian Flu - Hong Kong Flu - 2009 flu pandemic

Epidemics Russian flu (1977–1978) - Fujian flu (H3N2)

Non-human Mammals Canine influenza - Cat influenza - Equine influenza (2007 Australian outbreak) - Swine influenza

Non-mammals Avian influenza - Fujian flu (H5N1)

Related Influenza-like illness

Mi lista de blogs

En Barcelona sexy hot videos bikini hilary duff haley duff bikini 50 cent afi airline tickets akon al4a amazon amazon.com angelina jolie anime aol.com asian ask ask jeeves ask.com babes baby names barnes and noble bcs bed bath and beyond best buy beyonce bikini booty breaking news breast breasts briana banks britany spears britney britney crotch britney no panties paris britney spears crotch britney spears exposed britney spears flash britney spears flashing britney spears no panties britney spears panties britney spears photo britney spears photos britney spears pics britney spears pictures britney spears underwear brittany spears brooke burke candice michelle carmen electra carol of the bells carrie underwood cars cartoons catholic churches cats celebrity sedu hairstyles cheat codes cheerleader chris brown christina aguilera christmas lights music christmas songs christmas tree christmas wallpaper ciara circuit city city maps cleavage costco craigs list craigslist dane cook dictionary disturbed dog dogpile dogs dogs for sale driving directions ebay ebay.com ebony eminem eminem superman emma watson emoticons for msn eragon espn eva green eva longoria evanescence fall out boy family guy fergalicious fergie first name meanings flight simulator free games free music downloads free online games free search funny videos game cheats for ps2 games games play gift baskets gift ideas girl girls google google earth google.com gospel music lyrics green day gwen stefani hannah montana harry potter hi high school musical hilary duff hinder home depot home video hot hotmail hotmail.com how to save a life ipod ipod nano irreplaceable janet jackson jenna jenna jameson jennifer aniston jennifer aniston sedu hairstyles jennifer lopez jennifer lopez sedu hairstyles jenny mccarthy jessica alba jessica simpson jewelry jim jones jingle bell rock jojo jokes jordan capri justin timberlake kate beckinsale katie price kelly blue book kids kmart korn laptops lil wayne limewire lindsay lohan lingerie linkin park lips of an angel love lowes ls magazine ludacris lyrics lyrics music mad world manga map quest mapquest maps mariah carey mature meaning of names metallica models movies mp3 players msn msn.com music lyrics my chemical romance my space myspace myspace layouts myspace login myspace.com naruto nfl jerseys nickelback nintendo wii nudism nudist nudists obituaries one night in paris online games overstock.com pam anderson pamela anderson panic at the disco panties pantyhose paris hilton pc game cheats people search pink play game play games play the game lyrics playstaion2 cheats playstation game cheats playstation2 game cheats poetry pokemon pornotube ps 2 game cheats ps2 cheats codes psp pthc radio stations raven riley rihanna ringtones road map runescape salaries sams club santa search engine search engines sears sedu beauty tips sedu hair styles shakira shannon elizabeth slipknot smack that snow solia hair styling song lyrics south park southwest airlines spears staples stocking stuffers system of a down tara reid target target.com tenacious d tera patrick terrier test text messages the game thong thongs three days grace tony hawk topless torrie wilson toys r us trish stratus triviabucks vida guerra walk it out walmart walmart.com we fly high we live together weather webkinz wedding speech weird al weird al yankovic white and nerdy white pages wicked weasel wii wikipedia wind it up women colegialas schoolgirs