Most human Asian HPAI H5N1 cases have presented for medical care late in their illness and have been hospitalized with severe respiratory d… Billions of U.S. dollars are being raised and spent to research H5N1 and prepare for a potential avian influenza pandemic. Le ministère de la Santé de la province d'Alberta, au Canada, a confirmé le décès le 3 janvier dernier d'un Canadien touché par la grippe aviaire H5N1. It was the first H7N9 outbreak reported in humans. HA codes for hemagglutinin, an antigenic glycoprotein found on the surface of the influenza viruses and is responsible for binding the virus to the cell that is being infected. Genotype Z emerged in 2002 through reassortment from earlier highly pathogenic genotypes of H5N1[2] that first infected birds in China in 1996, and first infected humans in Hong Kong in 1997. Detection of bird flu A less severe form of disease associated with H7N7, for example, was reported in the Netherlands in 2003, where it caused one human death but led to the culling of thousands of chickens; since then the virus has been detected in the country on several occasions. The report stated the virus may sometimes stick to surfaces or get kicked up in fertilizer dust to infect people. H5N1 is a subtype of the species Influenza A virus of the genus Alphainfluenzavirus of the family Orthomyxoviridae. [55] Tamiflu-resistant strains have also appeared in the EU, which remain sensitive to Relenza. [73][74][75] The papers by Fouchier and Kawaoka conclude that it is entirely possible that a natural chain of mutations could lead to an H5N1 virus acquiring the capability of airborne transmission between mammals, and that a H5N1 influenza pandemic would not be impossible. Clusters of human Asian HPAI H5N1 cases, (usually 2 cases but ranging from 2-8 cases per cluster), have been identified in several countries. After Fouchier offered an article describing this work to the leading academic journal Science, the US National Science Advisory Board for Biosecurity (NSABB) recommended against publication of the full details of the study, and the one submitted to Nature by Yoshihiro Kawaoka of the University of Wisconsin describing related work. Informations sur votre appareil et sur votre connexion Internet, y compris votre adresse IP, Navigation et recherche lors de l’utilisation des sites Web et applications Verizon Media. [21] The severity of the infection depends in large part on the state of the infected persons' immune systems and whether they had been exposed to the strain before (in which case they would be partially immune). 2005 – LPAI H5N1 was detected in ducks in Manitoba, Canada. pneumonia and respiratory failure) and death in some people. • Il peut y avoir une augmentation du nombre de cas chez les humains en même temps que chez les oiseaux. Both the H2N2 and H3N2 pandemic strains contained avian influenza virus RNA segments. La plupart des virus de la grippe aviaire ne sont pas pathogènes pour l’homme. [47], Ongoing detailed mutually coordinated onsite surveillance and analysis of human and animal H5N1 avian flu outbreaks are being conducted and reported by the USGS National Wildlife Health Center, the Centers for Disease Control and Prevention, the World Health Organization, the European Commission, and others. The dominant strain of annual flu virus in January 2006 was H3N2, which is now resistant to the standard antiviral drugs amantadine and rimantadine. "Since 1997, studies of influenza A (H5N1) indicate that these viruses continue to evolve, with changes in antigenicity and internal gene constellations; an expanded host range in avian species and the ability to infect felids; enhanced pathogenicity in experimentally infected mice and ferrets, in which they cause systemic infections; and increased environmental stability. The remaining 22 isolates all fall into a third, clearly distinct clade, labeled EMA, which comprises samples from Europe, the Middle East, and Africa. CDC twenty four seven. Through antigenic drift, H5N1 has mutated into dozens of highly pathogenic varieties divided into genetic clades which are known from specific isolates, but all belong to genotype Z of avian influenza virus H5N1, now the dominant genotype. In most cases, it causes minor sickness or no noticeable signs of disease in birds. There are several H5N1 vaccines for several of the avian H5N1 varieties, but the continual mutation of H5N1 renders them of limited use to date: while vaccines can sometimes provide cross-protection against related flu strains, the best protection would be from a vaccine specifically produced for any future pandemic flu virus strain. However, WHO expert Hassan al-Bushra has said: Animal and lab studies suggest that Relenza (zanamivir), which is in the same class of drugs as Tamiflu, may also be effective against H5N1. Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website. [39][40] A previously uncontagious strain may then be able to pass between humans, one of several possible paths to a pandemic. Of the few avian influenza A viruses that have crossed the species barrier to infect humans, Asian HPAI H5N1 virus has caused the largest number of detected cases of severe disease and death in humans. H5N1, the cause of the 1997 bird flu outbreak in Hong Kong, was first identified in terns in South Africa in 1961. More On H5N1. [56][57], The earliest infections of humans by H5N1 coincided with an epizootic (an epidemic in nonhumans) of H5N1 influenza in Hong Kong's poultry population in 1997. Clade 2 viruses were first identified in bird isolates from China, Indonesia, Japan, and South Korea before spreading westward to the Middle East, Europe, and Africa. Bird flu, also called avian influenza, a viral respiratory disease mainly of poultry and certain other bird species, including migratory waterbirds, some imported pet birds, and ostriches, that can be transmitted directly to humans. Normally, a highly pathogenic avian virus is not highly pathogenic to either humans or nonpoultry birds. 1975 – LPAI H5N1 was detected in a wild mallard duck and a wild blue goose in Wisconsin. Virus-contaminated surfaces and intermediate hosts such as pigs can also be sources of infection for humans. "[67], The New York Times, in an article on transmission of H5N1 through smuggled birds, reports Wade Hagemeijer of Wetlands International stating, "We believe it is spread by both bird migration and trade, but that trade, particularly illegal trade, is more important". In Arctic temperatures, it does not degrade at all. Although isolated instances of person-to-person transmission appear to have occurred since 1997, sustained transmission has not been observed. H5N1 as an avian virus preferentially binds to a type of galactose receptors that populate the avian respiratory tract from the nose to the lungs and are virtually absent in humans, occurring only in and around the alveoli, structures deep in the lungs where oxygen is passed to the blood. [12] The inflammatory cascade triggered by H5N1 has been called a 'cytokine storm' by some, because of what seems to be a positive feedback process of damage to the body resulting from immune system stimulation. March 2013; Chemical & Engineering News 90(8) DOI: 10.1021/cen-09008-editorial. [14] At least 12 companies and 17 governments are developing prepandemic influenza vaccines in 28 different clinical trials that, if successful, could turn a deadly pandemic infection into a nondeadly one. ", "HHS ties pandemic mitigation advice to severity", "Pathology, Molecular Biology, and Pathogenesis of Avian Influenza A (H5N1) Infection in Humans", Protecting Poultry Workers from Avian Influenza (Bird Flu), "H5N1 Virus Attachment to Lower Respiratory Tract", "Is Exposure to Sick or Dead Poultry Associated With Flulike Illness? Découvrez comment nous utilisons vos informations dans notre Politique relative à la vie privée et notre Politique relative aux cookies. • Presque tous les cas humains viennent d’un contact direct avec une volaille malade, ou In 2003, world-renowned virologist Robert G. Webster published an article titled "The world is teetering on the edge of a pandemic that could kill a large fraction of the human population" in American Scientist. Influenza A viruses are significant for their potential for disease and death in humans and other animals. The H5N1 virus, however, appears to be resistant to at least two of the drugs, amantadine and rimantadine. "While the pandemic human influenza viruses of 1957 (H2N2) and 1968 (H3N2) clearly arose through reassortment between human and avian viruses, the influenza virus causing the 'Spanish flu' in 1918 appears to be entirely derived from an avian source".[42]. This panzootic (a disease affecting animals of many species, especially over a wide area) outbreak was stopped by the killing of the entire domestic poultry population within the territory. This has been reported to have occurred in a home and in a hospital room. Severe infection can result in conjunctivitis or such life-threatening complications as bacterial or viral pneumonia and acuterespiratory illness. Vous pouvez modifier vos choix à tout moment dans vos paramètres de vie privée. ", "Breaking News: NSABB Reverses Position on Flu Papers", "Bird Flu Scientist has Applied for Permit to Export Research", "Journal Publishes Details on Contagious Bird Flu Created in Lab", "Airborne Transmission of Influenza A/H5N1 Virus Between Ferrets", "Scientists create bird flu that spreads easily among mammals", "Chinese Scientists Create New Mutant Bird-Flu Virus", Poultry sector suffers despite absence of bird flu, "Italy imposes controls after bird flu discovery", International Institute for Sustainable Development (IISD), "The response to bird flu: Too much or not enough?