Whether direct viral dissemination to bone marrow bm cells causes this phenomenon remains elusive. A birdadapted strain of h5n1, called hpai a h5n1 for highly pathogenic avian influenza virus of type a of subtype h5n1, is the highly pathogenic causative agent of h5n1 flu, commonly known as avian influenza bird flu. Avian influenza, human cases in indonesia may 16th, 2007 source. Avian influenza virus h5n1 replication in feathers of. August 2008 appendix 1 avian influenza surveillance and response.
Confirmed human cases of avian influenza a h5n1 the world health organization who maintains a chart showing the latest number of laboratory confirmed human cases of h5n1 by country. Recent outbreaks of avian influenza a h5n1 in poultry throughout asia have had major economic and health repercussions. A highly pathogenic avian influenza a h5n1 virus has crossed the species barrier to cause deaths in humans in asia and poses an increasing threat of a pandemic. In 2016, an epidemic of highly pathogenic avian influenza a virus subtype h5n8 in the netherlands caused mass deaths among wild birds, and several commercial poultry farms and captive bird holdings were affected. Avian influenza viruses are classified as either low pathogenic also called low pathogenicity avian influenza viruses or highly pathogenic high pathogenicity avian influenza viruses. We explore the susceptibility of the two stem cell types. It is often referred to simply as bird flu or avian influenza, even though it is only one of many subtypes. Highly pathogenic asian avian influenza ah5n1 virus. Background recent outbreaks of avian influenza a h5n1 in poultry throughout asia have had major economic and health repercussions. Maximumparsimony mp, maximumlikelihood ml, and neighborjoining nj analyses were.
World health organization who, csr, disease outbreak news. Nearly 600 cases of human h5n1 have been reported, worldwide, since 2003. There have been more than 600 documented cases of avian influenza a h5n1 since december 2003 and more than cases of avian ah7n9 influenza from february to may 20. Influenza a viruses can cause three distinct diseases in humans. Some avian influenza viruses circulate in wild bird populations causing no disease or only mild disease. Wild waterfowl, including ducks and geese, are natural hosts of ai virus of all 16 hemagglutinin subtypes in nature 2,3.
The incubation period for influenza a infection is short, the order of days, pandemics can be established in weeks. For each of the countries affected by the avian influenza h5n1 epidemic of 2003. Appendix 1 avian influenza surveillance and response infectious disease epidemiology program. A the ability of avian influenza h5n1 to infect mscs was compared to human influenza viruses. Avian influenza h5n1 and agricultural workers october 2005 i believe that the momentum that is now building up will give us a chance to change the course of history and head off a pandemic caused by the h5n1 virus. Recently 2004 it has affected japan, south korea, taiwan, vietnam, thailand, combodia, indonesia, pakistan, laos and china. The disease can vary from mild to severe, depending on the virus strain involved. Seventeen avian species and two mammalian species were intranasally inoculated with the zoonotic achickenhong kong22097 chickenhk h5n1 avian influenza ai virus in order to ascertain a. Outbreaks of avian influenza viruses later increased in frequency. The study explored the prevalence of influenza viruses in felid species. The most severe strain, called highly pathogenic avian influenza hpai, is. Dec 10, 20 avian influenza could infect and replicate in mscs.
There have been four influenza pandemics since the early 20 th century, and each has been caused by the emergence of a novel virus. Avian influenza virus ah5n1 is a public health threat that has the potential to cause serious illness and death in humans. Understanding its pathology, transmission, clinical features. Avian influenza bird flu what is avian influenza and what causes it. Highly pathogenic asian avian influenza ah5n1 virus avian. In egypt, avian influenza a subtype h5n1 and h9n2 viruses are enzootic in. The worldwide spread of h5n1 avian influenza has raised concerns that this virus might acquire the ability to pass readily among humans and cause a. Unfortunately there is now much confusion about the different human diseases caused by influenza viruses. The virus was first detected in 1996 in geese in chi. Although it is a bird flu, it has infected a relatively small number of people killing around. Avian influenza frequently asked questions who world health organization overview of avian influenza, the effects on birds, and the possibility of h5n1 becoming the next influenza pandemic for humans.
The first known cases in humans were reported in 1997, when an outbreak of avian influenza a virus subtype h5n1 in poultry in hong kong led to severe illness in 18. The presence of abnormal hematologic findings such as lymphopenia, thrombocytopenia, and pancytopenia were diagnosed in severe cases of avian influenza a h5n1. Infections due to some of these strains have been detected in humans. In 1997 and again since 2003, there has been concern about the the influenza ah5n1 virus which continues to circulate causing outbreaks in birds and occasional human infections. Since their reemergence in 2003, highly pathogenic avian influenza a h5n1 viruses have reached endemic levels among poultry in several southeast asian countries and have caused a still increasing number of more than 100 reported human infections with high mortality. A virus is defined as hpai or lpai by its ability to cause severe disease in intravenously inoculated young chickens in the laboratory, or by its.
Influenza a viruses from pigs can also infect humans. Human cases of h5n1 avian influenza occur occasionally, but it is difficult to transmit the infection from person to person. Avian influenza is caused by strains of influenza a that normally infect only wild birds and domestic poultry. Surveillance plan for the early detection of h5n1 highly pathogenic. Hpai h5n1 is also one of the few avian influenza viruses that has crossed the species barrier and infected humans. The first documented infection of humans with an avian influenza virus occurred in hong kong in 1997, when the h5n1 strain caused severe respiratory disease in 18 humans, of whom 6 died. Clinical signs of the disease depend on the strain and subtype of virus and. Approaches to controlling, preventing and eliminating h5n1 highly pathogenic avian influenza in endemic countries.
Currently, highly pathogenic h5n1, a specific strain of avian. Although h5n1 highly pathogenic avian influenza hpai virus has been known for over a. We examined feathers of domestic ducks and geese inoculated with 2 different avian influenza virus h5n1 genotypes. Avian h5n1 influenza avian influenza bird flu is a disease caused by viruses that primarily infect birds but may also infect other animals, including humans. H5n1 virus may be adapting to pigs in indonesia cidrap. However, the actual risk of such a pandemic remains undetermined. Risk factors of current importance in the epidemiology of h5n1. Highly pathogenic avian influenza hpai h5n1 has caused a large number of outbreaks. Avian influenza update information medical ecology. Human infections with this virus were identified in vietnam in j.
Tropism of avian influenza a h5n1 virus to mesenchymal. In the 1957 and 1968 pandemics, the new viruses contained components of previous human, as well as avian, influenza viruses. In the midst of ongoing concerns about the h5n1 virus adapting to humans and causing a pandemic, a new influenza virus h1n1 emerged from the americas. This page will be updated when information is available.
The virus was first detected in 1996 in geese in china. There are many types of influenza viruses that usually only infect birds. Avian influenza a viruses are frequently transmitted to domestic fowl from the natural wild life reservoirs, and also to pigs from domestic fowl. Together with virus isolation from the skin, the detection of viral antigens and ultrastructural observation of the virions in the feather epidermis raise the possibility of feathers as sources of infection. Egypt today reported its first highly pathogenic h5n8 avian influenza detection, making it the third country in the middle east to report the new h5 clade, which has also spread to several european countries after it was first identified in russian migratory birds in june. Asian h5n1 was first detected in humans in 1997 during a poultry outbreak in hong kong and has since been detected in poultry and wild birds in more than 50 countries in. Learn about bird flu viral subtypes and their detection. The structure of h5n1 avian influenza neuraminidase. It also underscores the need for the development of. Update on highly pathogenic avian influenza in animals type h5 and h7 external.
Aug 10, 2010 in 1997 and again since 2003, there has been concern about the the influenza a h5n1 virus which continues to circulate causing outbreaks in birds and occasional human infections. Since 1997, an epidemic of avian influenza ai virus subtype h5n1 has spread in asia, causing fatal infections in poultry, wild birds, mammals, and humans. Avian influenza a h5n1 in 10 patients in vietnam nejm. Influenza a virus subtype h5n1 a h5n1 is a subtype of the influenza a virus which can cause illness in humans and many other animal species.
His research interests include molecular epidemiology and hostpathogen interaction of avian influenza viruses. Outbreaks of highly pathogenic avian influenza ah5n8 in. Avian influenza a virus h5n1 outbreaks, kuwait, 2007. Pdf gao, hainv lu, hongzhou cao, bin du, bin shang, hong gan, jian he lu, shuihua yang, yida fang, qiang shen, yinzhong. The world has now had more than 10 years of experience with human infection with avian influenza ah5n1, and a little more than 2 years of experience with avian influenza ah7n9. Highly pathogenic avian influenza hpai virus h5n1 has been endemic in. Since their reemergence in 2003, highly pathogenic avian in.
The structure of h5n1 avian influenza neuraminidase suggests. In light of a number of existing publications on h1n1 and h5n1, its difficult to fully understand the hesitancy to publish the ferret h5n1 infection papers, but caution is never a. Avian influenza is a viral disease that can affect bird species throughout the world. Human and avian influenza a viruses can infect pigs and reassortment can occur in pigs between avian, swine and human influenza a viruses. One strain of avian influenza currently identified in asia and europe is known as influenza a h5n1. Comprehensive analysis of antibody recognition in convalescent humans from highly pathogenic avian influenza h5n1 infection article pdf available in nature communications 6. Asian highly pathogenic avian influenza hpai ah5n1 virus occurs mainly in birds and is highly contagious among them. May 01, 2012 the incubation period for influenza a infection is short, the order of days, pandemics can be established in weeks. Lists of countries affected by h5n1 plus case counts of h5n1 in humans.
H5n1 avian influenza statistics latest case counts for humans, plus lists of countries affected by h5n1. Emergency prevention plan for the fight against avian influenza in rwanda pdf 45 pp march 2006 the plan aims to define strategies, measures and activities for safeguarding both animal and human health, using a multidisciplinary, flexible approach. Wild birds and avian influenza food and agriculture organization. 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. The phylogenetic tree was generated using the neighbourjoining. H5n1 is a type of influenza virus that causes a highly infectious, severe respiratory disease in birds called avian influenza or bird flu. Epidemiology of h5n1 avian influenza in asia and implications for. The most severe strain, called highly pathogenic avian influenza hpai, is caused by viruses with h5. Psychiatric aspects of the impending avian flu pandemic. It was setup as a result of the outbreak in hong kong. August 2008 appendix 1 avian influenza surveillance and.
The global strategy for the prevention and control of h5n1 highly pathogenic avian influenza october 2008 pdf html march 2007 pdf html global programme for the prevention and control of h5n1 highly pathogenic avian influenza. Lee is a postdoctoral researcher at the southeast poultry research laboratory, usda agricultural research service, athens, georgia, usa. Humantohuman transmission is limited, most cases are acquired from animals, typically poultry. Pdf avian influenza a h5n1 infection in humans researchgate. Molecular identification of avian influenza virus subtypes h5n1 and. Highly pathogenic avian influenza hpai is a highly infectious viral disease that affects a wide range of bird species. Highly pathogenic avian influenza virus in migratory birds in the united states. Avian influenza could infect and replicate in mscs.
Aug 16, 2006 the worldwide spread of h5n1 avian influenza has raised concerns that this virus might acquire the ability to pass readily among humans and cause a pandemic. As of wed 16 may 2007, who can now confirm 15 additional cases, including deaths, of human infection with h5n1 avian influenza that occurred in indonesia from the end of january 2007 up to the present and has updated its table of confirmed human cases accordingly. Pdf comprehensive analysis of antibody recognition in. Many scientists believe that conditions are ripe today for a pandemic of avian influenza.
Program pnsa manual for the contingency of avian influenza and. Multiple reassorted viruses as cause of highly pathogenic. Fao h5n8 hpai global situation update fao emergency. First documented human infection with avian influenza virus was in 1997 in hong kong where 18 people were affected out of which 4 died. This disease has been identified over a century ago in italy. The spread of highly pathogenic h5n1 avian influenza into asia. This guidance was prepared in the event that highly pathogenic avian influenza h5n1 is introduced into the united states through returning trav elers or poultry. Mar 31, 2009 cidrap news scientists report that h5n1 avian influenza viruses may be adapting to pigs, as evidenced by the finding that h5n1 viruses isolated from pigs in indonesia were less harmful to mice than were h5n1 viruses from chickens.
Avian influenza ah5n1 virus in egypt centers for disease control. The speed with which these diseases can emerge and spread presents serious public health, economic, and development concerns. In light of a number of existing publications on h1n1 and h5n1, its difficult to fully understand the hesitancy to publish the ferret h5n1 infection papers, but caution is never a bad thing. Timeline of major events 25 january 2012 early events date events in animals events in humans 1996 highly pathogenic h5n1 virus is isolated from a farmed goose in guangdong province, china.
Shigeru omi, world health organization regional director for the western pacific, manila, october 14, 2005 1. We performed complete genome sequencing to study the relationship between the wild bird and poultry viruses. Tropism of avian influenza a h5n1 virus to mesenchymal stem. August 2008 appendix 1 avian influenza surveillance and response infectious disease epidemiology program 350 capitol st, room 125, charleston wv 2530715. Some avian influenza viruses, such as h5n1 or h7n9, have been associated with human disease. Predicting the global spread of h5n1 avian influenza pnas. Since then, 2 lesser pandemics have occurred, the last more than 40 years ago. Basic information on avian influenza excerpts from world. Highly pathogenic asian avian influenza ah5n1 in people. Phylogenetic analysis showed that the viruses are related to h5 clade 2. Bird flu is often used synonymously with avian influenza ai, however, bird flu specifically refers to the hpai h5n1 strain that has killed millions of birds. The highly pathogenic influenza a virus subtype h5n1 is an emerging avian influenza virus that is causing global concern as a potential pandemic threat. Department of agriculture usda is working with its partners on the international and domestic fronts to help control the spread of highpathogenicity h5n1 avian influenza. Mar 31, 2009 mar 31, 2009 cidrap news scientists report that h5n1 avian influenza viruses may be adapting to pigs, as evidenced by the finding that h5n1 viruses isolated from pigs in indonesia were less harmful to mice than were h5n1 viruses from chickens.
Pdf gao, hainv lu, hongzhou cao, bin du, bin shang, hong gan, jianhe lu, shuihua yang, yida fang, qiang shen, yinzhong. The pattern of highly pathogenic avian influenza h5n1. Asian h5n1 was first detected in humans in 1997 during a poultry outbreak in hong kong and has since been detected in poultry and wild birds in more than 50 countries. Avian influenza bird flu is a disease caused by viruses that primarily infect birds but may also infect other animals, including humans. Feb 27, 2020 bird flu, a viral respiratory disease of poultry and other bird species, including migratory waterbirds, that can be transmitted to humans. One strain of avian influenza currently identified in asia and europe is known as influenza ah5n1.
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