The hospitalisation rate during the 20092010 season was 5. International updates avian influenza published by the world health organization who. H1n1 influenza virus news and updates from the economic times. Additional ah1n1pdm09 and ah3n2 clinical samples are tested for mutations of the virus known to confer oseltamivir resistance.
Viral evolution is facilitated by animals such as pigs and birds, which serve as reservoirs of various subtypes and strains of influenza a viruses. Infect humans during the autumnwinter months when they are most likely to get infected. People do not normally get swine flu, but human infections can and do happen. The 2009 influenza pandemic ah1n1pdm09 of swine origin and the continued circulation of highly pathogenic avian h5n1 strain in humans are. This system is not errorfree overtriage or undertriage. How the influenza virus spreads american red cross. The current h1n1 virus strain is a mixture of human, pig and bird genes and has proved to be very contagious, but no more deadly than common seasonal flu viruses. Most flu viruses have strong seasonality and a preference for temperate. In june 2009, the world health organization who issued a pandemic alert concerning the spread of an influenza a h1n1 virus that showed distinctive. Howard hughes medical institute investigator robert lamb, a virologist and influenza expert at northwestern university, has followed the current outbreak closely.
Next generation sequencing at cdc revealed a new seasonal human influenza ah3n2 and a h1n1 pdm09 reassortant virus, rather than an influenza ah3n2 variant virus of swine origin. It has been suggested already in the early 1990s that at about the time of the spanish flu an avian influenza virus had crossed the species barrier from birds to pigs. Pdf we investigated the survival of a pandemic strain of influenza a h1n1 on a variety of common. Novel swineorigin influenza a h1n1 virus investigation teamemergence of a novel swineorigin influenza a h1n1 virus in humans.
After the pandemic subsided, sporadic cases of human influenza h1n1 continued to occur worldwide. Explore h1n1 influenza virus profile at times of india for photos. Washington cnn president obama has declared a national emergency to deal with the rapid increase in illness from the h1n1 influenza virus. A swine influenza outbreak occurred on a commercial pig farm in thailand. Global dissemination of the virus was further expedited by the unprecedented rates of passenger travel. An influenza pandemic can happen when a novel flu virus emerges, such as a swine flu. Its your health avian influenza is a short, easytoread fact sheet. However, just as the common, seasonal flu that affects humans is constantly mutating as our immune systems and vaccines compromise weaker strains, swine flu is always trying to improve itself so that it can become more virulent, spread faster. Pdf the survival of influenza ah1n1pdm09 virus on 4. Swine flu is an influenza virus that usually affects pigs. Influenza a h1n1 is subject to antigenic driftconstant, rapid viral evolution driven by mutations in the genes that encode the h and n antigen proteins.
Lung histopathological findings in fatal pandemic influenza a h1n1. Second was to address whether meat, blood and tissue from pigs infected with the new 2009 h1n1 influenza a virus would be free of infectious virus. Infections with influenza a viruses iav are still amongst the major causes of highly contagious severe respiratory diseases not only bearing a devastating effect to human health, but also significantly impact the economy. Influenza a h1n1 virus is the subtype of influenza a virus that was the most common cause of human influenza flu in 2009. Besides vaccination that represents the best option to protect from iav infections, only two classes of antiinfluenza drugs, inhibitors of the m2 ion channel and the. Swine flu or h1n1 influenza is a declared pandemic across the world. Pandemic influenza is a global outbreak of new human influenza. Learning from the 2009 h1n1 influenza pandemic the new rms. Influenza a h1n1 virus, a subtype of influenza virus a, is the most common cause of influenza in humans. All structured data from the file and property namespaces is available under the creative commons cc0 license. Reassortment occurs when two influenza viruses infect a single host cell and exchange gene segments, creating a new virus.
Pdf on feb 1, 2012, ma eugenia manjarrez and others published start of a. Influenza is unpredictable, but this flu season could be worse than recent years because of the 2009 h1n1 virus. Influenza pandemic h1n1 of 2009, also called h1n1 flu, byname swine flu, the first major influenza outbreak in the 21st century, noted for its rapid global spread, which was facilitated by an unusually high degree of viral contagiousness. Preparing for the flu centers for disease control and. Plan for financial impacts associated with the 20092010 flu season and 2009 h1n1 flu response. Testing of influenza ah1n1pdm09, ah3n2, and influenza b virus isolates for resistance to neuraminidase inhibitors oseltamivir, zanamivir, and peramivir is performed at cdc using a functional assay. A strain of swineorigin h1n1 was responsible for the 2009 flu pandemic. A fresh analysis finds that the death toll from the h1n1 swine flu in 200910 was severely underestimated. On march 28, one month before news of the swine flu outbreak headlined worldwide, a nineyearold girl in imperial county, california, ran a fever of 104. Consider the impact of the 20092010 flu season, 2009 h1n1 flu response, and other unforeseen emergencies that can lead to a shortage of funds. Influenza a virus, whose devastating effect reflected significantly in mexico city. Click here to download the 11 x 17 pdf file so that you can print and post it in. It is an orthomyxovirus that contains the glycoproteins haemagglutinin.
Influenza a virus h1n1 wikispecies, free species directory. Origin of the 1918 pandemic h1n1 influenza a virus as studied by. Files are available under licenses specified on their description page. Influenza humana a h1n1, su profilaxis y tratamiento. This page is not intended as a standalone web document and is intended to serve merely as a section 508accessible version of the powerpoint presentation 2009 h1n1. In march and early april 2009 a new swineorigin influenza virus soiv, a h1n1, emerged in mexico and the usa. This strain is often called swine flu by the public media. For this reason, they are described as h1n1, h1n2 etc. Three to 5 million people suffer from severe illness and 0. No evidence of gene reassortment or pigtohuman transmission of pandemic h1n1 2009 virus was found during the outbreak. The subtypes of influenza virus are h1n1, h1n2, h3n1, h3n2, h2n3 and h5n1, etc 24. History suggests that the 2009 pandemic h1n1 influenza virus faces extinction unless it mutates to avoid already high global population immunity.
National center for immunization and respiratory diseases, influenza division ncirdid. In virology, influenza a virus subtype h1n1 a h1n1 is the subtype of influenza a virus that was the most common cause of human influenza flu in 2009, and is associated with the 1918 flu pandemic it is an orthomyxovirus that contains the glycoproteins haemagglutinin and neuraminidase. In contrast with the 1918 h1n1 influenza virus, the 2009 h1n1 strain was generated by reassortment between two wellestablished swine influenza. However, just as the common, seasonal flu that affects humans is constantly mutating as our immune systems and vaccines compromise weaker strains, swine flu is always trying to improve itself so that it can become more virulent. Within a short time of the initial emergence of ah1n1pdm09 virus, novel reassortants were isolated from swine. Public health agency of canadas avian influenza page offers frequently asked questions faqs, travel health advisories and outbreak updates. Each winter, influenza viruses infect 5 to 15% of the worlds population and are a substantial threat to human health. Influenza the flu is a contagious respiratory illness caused by influenza viruses. Influenza suina influenza a virus h1n1 giant microbes. The pandemic h1n1 2009 influenza a virus ph1n1 2009 virus is antigenically unrelated to human seasonal influenza viruses but genetically related to viruses that have been circulating in swine for a number of yearsnorth american h3n2 triple reassortment, classical swine h1n1 lineage, and the eurasian avianlike swine h1n1 virus garten 2009. Geographic dependence, surveillance, and origins of the. Department of human services h1n1 resource center nj. Innards of h1n1 virus resemble flu sausage live science. The pandemic influenza ah1n1 2009 virus was confirmed in all deceased patients.
In virology, the pandemic h1n109 virus is a swine origin influenza a virus subtype h1n1 strain that was responsible for the 2009 swine flu pandemic. Few people seemed afraid of the h1n1 influenza virus in 2009, which, while unusually mild, infected as many as a hundred million americans and nearly a billion people throughout the world. Cdc is preparing for an early flu season and expects both 2009 h1n1 flu and seasonal flu to. Sporadic cases of human infection with swine influenza virus have been reported in the united states and elsewhere. Influenza a and b viruses evolve rapidly and evade the host immunity by continuous accumulation of point mutations within the genes coding for. In virology, influenza a virus subtype h1n1 ah1n1 is the subtype of influenza a virus that was the most common cause of human influenza flu in 2009, and is associated with the 1918 spanish flu outbreak it is an orthomyxovirus that contains the glycoproteins haemagglutinin and neuraminidase. The 1918 pandemic, caused by worldwide spread of a human influenza a h1n1 virus, was responsible for 4050 million deaths. Influenza ah1n1pdm09 virus recovery from 4 surfaces over time. This reporting period, influenza a remains the predominant influenza virus type nationally, with the distribution of the influenza ah1n1pdm09 and ah3n2 subtypes varyingby jurisdiction. All about influenza suina influenza a virus h1n1 facts. Swine influenza is a common and widely dispersed disease of pigs 1 3. In silico molecular modeling of neuraminidase enzyme h1n1.
For more information 3 influenza viruses are rna viruses belonging to the orthomyxoviridae family, with myxo referring to the fact. The pandemic influenza a h1n1 2009 virus is the first public health emergency of international concern to occur since the revised ihr came into force. In 2009 a strain of swine flu called h1n1 infected many people around the world. The pandemic h1n1 virus exhibited several unusual characteristics. The virus is contagious and can spread from human to. Now, with an intensifying outbreak driven by the emergence of a new strain of influenza ah1n1, scientists once again have a unique opportunity to study viral evolution in action. Dhss has added to its website a free, online pandemic influenza webinar to. The virus is also engaged incontagious diffusion, spreading out within each new country. A plant extract of ribes nigrum folium possesses anti. These images provide a 3d graphical representation of the biology and structure of a generic influenza virus, and are not specific to the 2009 h1n1 virus. Viral gene sequences to assist update diagnostics for swine influenza ah1n1 pdf. Classical swine influenza virus infections are enzootic among pigs in north america. In virology, influenza a virus subtype h1n1 ah1n1 is the subtype of influenza a virus that. For other names, see the nomenclature section below.
Influenza a virus subtype h3n1 the known subtypes of influenza a virus that create influenza in pigs and are endemic in pigs are h1n1, h1n2, h3n1 and h3n2. An influenza virus binds to a respiratory tract cell. Also, having a disability alone may not make someone at higher risk for complications from the h1n1 virus. In wa there continues to be an increasing proportion of ah3n2, whereas in nsw there is a higher proportion of influenza ah1n1pdm09 being reported.
1274 146 905 294 626 483 710 1126 1592 684 1521 418 1151 494 1033 490 1016 508 1021 322 237 624 325 386 919 968 1251 1323 1324 446 564 1461 471 280 1357 641 176 1145