Influenza A virus subtype H7N2

H7N2 is a subtype of the species Influenza A virus (sometimes called bird flu virus).

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Outbreaks of H7N2

One person Virginia, US in 2002 and one person in New York, US, in 2003 were found to have serologic evidence of infection from H7N2; both fully recovered.

In February 2004, an outbreak of low pathogenic avian influena (LPAI) A (H7N2) was reported on 2 chicken farms in Delaware and in four live bird markets in New Jersey supplied by the same farms. In March 2004, surveillance samples from a flock of chickens in Maryland tested positive for LPAI H7N2. It is likely that this was the same strain. ^[1]

A CDC study following the 2002 outbreaks of H7N2 in commercial poultry farms in western Virginia concluded:

An important factor contributing to rapid early spread of AI virus infection among commercial poultry farms during this outbreak was disposal of dead birds via rendering off-farm. Because of the highly infectious nature of AI virus and the devastating economic impact of outbreaks, poultry farmers should consider carcass disposal techniques that do not require off-farm movement, such as burial, composting, or incineration. ^[2]

On 24 May 2007, an outbreak of H7N2 was confirmed at a poultry farm near Corwen, in Wales from tests on chickens that died from H7N2. The owners of the Conwy farm bought 15 Rhode Island Red chickens two weeks prior but all died from H7N2. The 32 other poultry at the site were slaughtered. A one kilometer exclusion zone was put in force around the property in which birds and bird products cannot be moved and bird gathering can only take place under licence. Nine people who were associated with the infected or dead poultry and reported flu-like symptoms were tested. Four tested positive for evidence of infection from H7N2 and were successfully treated for mild flu.^[3] In early June it was discovered that the virus had spread to a poultry farm 70 miles (113 km) away near St. Helens in north-west England. All the poultry at the farm were slaughtered and a 1 km exclusion zone imposed.^[4]

Sources

• CDC avian flu information

Further reading

• Research Update on H7n2 Avian Influenza Virus in Turkeys and Chickens
• Epidemiology of an H7N2 Avian Influenza Outbreak in Broilers in Pennsylvania in November 2001- January 2002
• Avian influenza H7N2 in Wales and the Northwest of England
• North Wales bird flu outbreak ends