H5N2

H5N2 is a subtype of the species Influenzavirus A (avian influenza virus or bird flu virus).

Low pathogenic avian inluenza H5N2 virus in poultry later gained accentuated virulence in the United States and Mexico. A highly pathogenic strain of H5N2 caused flu outbreaks with significant spread to numerous farms, resulting in great economic losses in 1983 in Pennsylvania, USA in chickens and turkeys, in 1994 in Mexico in chickens and a minor outbreak in 1997 in Italy in chickens.

In Korea, ducks have been destroyed at the farm since quarantine officials detected the suspected low pathogenic H5N2 strain of avian influenza on December 1, 2004.

In Japan, H5N2 virus was isolated or an anti-H5 antibody was identified from chickens in 40 chicken farms in Ibaraki Prefecture and in one chicken farm in Saitama Prefecture from June through December 2005. The strain was named as A/ chicken /Ibaraki/1/2005(H5N2).About 5.7 million birds were destroyed in Ibaraki following the H5N2 outbreaks.

It was reported on November 12, 2005 that "One of 2 birds found infected with bird flu in Kuwait has the H5N1 strain of the virus, authorities said. The infected bird was a migrating flamingo found on a Kuwait beach. The other was an imported falcon found to have the milder H5N2 variant."

In China, inactivated H5N2 has been used as a vaccine for H5N1.

In 2006, an H5N2 outbreak on a single farm in South Africa resulted in the destruction of all its sixty ostriches. The strain was similar to the one that caused outbreaks in South Africa 2004/2005.

In 2007, a low-pathogenic strain of H5N2 was found in samples collected from 25,000 turkeys in Pendleton County, West Virginia in a routine testing prior to their slaughter. The birds showed no sign of illness or mortality. Measures were taken to prevent the virus from mutating and spreading.

In late 2007 (December 21), an H5N2 outbreak was found in the Dominican Republic, in a Suburb of Higuey City, on the eastern side of the island. 15 roosters and 2 hens where eliminated even though they had no visible sign of infection.

In May and June 2008, there were three outbreaks of low-pathogenic H5N2 avian flu in birds at three locations in the central, northern, and southern parts of Haiti. "The outbreaks began on May 20 and appeared to be ongoing", as of June 17, 2008.

In Taiwan, outbreaks of H5N2 have been confirmed in December 2008.

Japan's Health Ministry said Jan, 2006 that poultry farm workers in Ibaraki prefecture may have been exposed to H5N2 (which was not previously known to infect humans) in 2005.Data were collected from 257 workers at 35 chicken farms by Ibaraki prefectural government. Using a Wilcoxon signed-rank test, it was determined that the H5N2 antibody titers of the second samples of paired sera were significantly higher than those of the first samples (p<0.001). The H5N2 antibody titers of paired sera of 13 subjects increased fourfold or more. The results suggest that this may have been the first avian influenza H5N2 infection from poultry to affect humans.