Transmission from wild birds to humans may be possible. Normally, avian flu viruses are passed among various species of shore birds, waterfowl and domestic birds, including poultry (chickens, turkeys, etc.). The H5N1 virus has also, on rare occasions, passed directly from domestic birds, especially chickens, to humans. This is most likely if the people are in close and regular contact with diseased poultry, as they would be in a chicken farming operation.

While currently there are unconfirmed reports of people being infected with H5N1 from dead wild birds, exposure to domestic and wild birds potentially infected with H5N1 should be avoided. The only documented cases of transmission to humans are from poultry; these cases include both highly pathogenic and low pathogenic strains of avian influenza. the present time, close contact with infected domestic poultry has been the primary way that people have become infected with the HPAI H5N1 virus.

Yes. The current strain has caused deaths in a number of wild bird species, mostly waterbirds. Most of these flock or nest in colonies on waterbodies or nearby farmland. Others are birds that often feed and scavenge in polluted waterways near towns and farms. Yet others are scavenging species that are likely to forage around poultry farms, such as crows and magpies.

Until now there has been no clear evidence to support this opinion but we can't ignore this possibility entirely. It seems that the spreading of the virus in South-East Asia is the result of transporting sick birds among farms. The locations in which the virus was isolated do not correspond with migration time and direction of wild birds. Nevertheless the recent cases in Europe were identified in locations that overlap with migration trails (including the Danube Delta).

Well over 100,000 healthy wild birds have been tested across South-east Asia in the last two years. Out of 16,000 living wild birds (mainly migratory) tested at the Mai Po Nature Reserve in Hong Kong between 1997 and 2004, none tested positive for HPAI H5N1. Of 850 samples (mainly faecal) from living wild birds tested at Lake Erhel, Mongolia in August 2005 (after an H5N1 outbreak), none was positive.

The H5N1 virus does not usually infect humans. In 1997. However, the first case of spread from a bird to a human was seen during an outbreak of bird flu in poultry in Hong Kong, Special Administrative Region. The virus caused severe respiratory illness in 18 people, 6 of whom died. Since that time, there have been other cases of H5N1 infection among humans.

The H5N1 virus currently infecting birds in Asia that has caused human illness and death is resistant to amantadine and rimantadine, two antiviral medications commonly used for influenza. Two other antiviral medications, oseltamavir and zanamavir, would probably work to treat flu caused by the H5N1 virus, but additional studies still need to be done to prove their effectiveness.

There currently is no commercially available vaccine to protect humans against the H5N1 virus that is being seen in Asia and Europe. However, vaccine development efforts are taking place. Research studies to test a vaccine to protect humans against H5N1 virus began in April 2005, and a series of clinical trials is underway. For more information about the H5N1 vaccine development process, visit the National Institutes of Health website.

No. Only 121 cases have occurred in the current outbreak despite huge numbers of birds being affected and numerous associated opportunities for human exposures, especially in backyard flocks. It is not understood why some people but not others become infected with similar exposures.

Drinking water has never been known to transmit any type of influenza virus. If infected birds were present in large numbers in a confined (not flowing) body of water, levels of contamination in that water could infect someone who drank the water without treating it. However, unfiltered or untreated water can carry a number of other pathogens that are far more likely to cause problems at this time.

Usually Avian Influenza viruses do not infect humans. Migratory birds act as carriers of these viruses and do not get affected by them. These birds then come in contact with domesticated birds such as chickens and turkeys and spread the infection to them. Domesticated birds may get the virus from contact with contaminated surfaces too. Once a virus infects domesticated birds, it can cause severe epidemic among the birds.

Use of infected poultry manure as fertiliser in agriculture and agriculture, and as feed in fish-farms and pig farms Most outbreaks in south-east Asia can be linked to movements of poultry and poultry products (or infected material from poultry farms, such as mud on vehicles, or peoples' shoes).

The H5N1 virus does not usually infect humans. In 1997, however, the first case of spread from a bird to a human was seen during an outbreak of bird flu in poultry in Hong Kong. The virus caused severe respiratory illness in 18 people, 6 of whom died. Since that time, there have been other cases of H5N1 infection among humans. Most recently, human cases of H5N1 infection have occurred in Thailand, Vietnam and Cambodia during large H5N1 outbreaks in poultry.

Transmission of HPAI through the handling of dead wild birds or their parts, such as feathers, is possible. Most human cases of HPAI have occurred in rural or peri-urban areas where many households keep small domestic poultry flocks. The HPAI virus is most often transmitted to humans through exposure during slaughter, defeathering, butchering and preparation of domestic poultry for cooking.

There are several ways to spread the virus from one geographical region to another: transporting the birds (and their feathers) to different poultry farms, the trafficking of captured wild birds and the involuntary transporting of soil on shoe soles and vehicle tires. Each of these ways of spreading the infection plays a certain part in the epidemic, but until now all cases were triggered by domestic and farm poultry transport.

Possibly ? but this is unproven and (evidence suggests) unlikely. If wild birds have any role, it is minor compared to other mechanisms. While a few outbreaks are consistent with the direction and timing of wild bird migration, most are not. The 2005 autumn migration came and went without migrating waterbirds spreading H5N1. The virus has not so far been reported from the birds' wintering areas in India, the Philippines, the Pacific and Africa.

The U.S. government is sampling wild birds in Alaska and other areas to look for H5N1 highly pathogenic avian influenza. The government expects to announce any detection of H5N1 even before the level of pathogenicity is determined and before it is determined if the strain is the Asian one. Therefore, an initial detection of H5N1 could turn out to be a low pathogenic, North American variety that has nothing to do with Asian avian influenza.

The H5N1 virus can improve its ability to infect humans when "reassortment" occurs, resulting in a new virus with enhanced human transmissibility. This is caused by an exchange of genetic material between human and avian influenza viruses when a human becomes infected with both at the same time. Pigs may also serve as "mixing vessels" for this exchange and then transmit the new virus to humans. Such an event would be announced by a sudden surge of cases with explosive spread.

There is no evidence to date that cats can spread H5N1 to humans. No cases of avian influenza in humans have been linked to exposure to sick cats, and no outbreaks among populations of cats have been reported. All of the influenza A (H5N1) infections in cats reported to date appear to have been associated with outbreaks in domestic or wild birds and acquired through ingestion of raw infected meat.

Influenza A (H5N1) virus – also called “H5N1 virus” – is an influenza A virus subtype that occurs mainly in birds. It was first isolated from birds (terns) in South Africa in 1961. Like all bird flu viruses, H5N1 virus circulates among birds worldwide, is very contagious among birds, and can be deadly.

The Advisory Committee on Dangerous Pathogens considers that the risk of transmission of AI from wild birds to the general public is small. However, to minimise any risk it is advisable to carry out general hygiene precautions when handling wild birds, such as wearing disposable protective gloves when picking up and handling carcases and washing hands, nails and forearms thoroughly with soap and water after handling the carcase.

The H5N1 virus does not usually infect humans. In 1997, however, the first case of infection from a bird to a human was identified during an outbreak of bird flu in poultry in Hong Kong. The virus caused severe respiratory illness in 18 people, 6 of whom died. Since that time, there have been other cases of H5N1 infection among humans. Most recently, human cases of H5N1 infection have occurred in Thailand, Vietnam, Cambodia, and Indonesia.

Currently no vaccine has been approved to provide protection against the H5N1 strain currently in Asia, although a number of candidates are in development. Anti-viral compounds such as amantadine, rimantadine, zanamavir and oseltamavir (Tamiflu) have shown some efficacy against other Influenza A viruses, and an initial study using oseltamavir on mice suggests that it may be effective against H5N1.

There currently is no vaccine to protect humans against the H5N1 virus that is being seen in Asia. However, vaccine development efforts are under way. Research studies to test a vaccine to protect humans against H5N1 virus began in April 2005. (Researchers are also working on a vaccine against H9N2, another bird flu virus subtype.) For more information about the H5N1 vaccine development process, visit the National Institutes of Health website.