H5N1 Strain of Bird Flu Confirmed in Japanese Outbreak

An outbreak of bird flu at a poultry farm in southwestern Japan was due to the lethal H5N1 strain of the virus, a farm ministry official said Tuesday, confirming the first such case to hit Japan in three years.

There have been no reported cases of human infection or additional outbreaks in poultry in Japan. Authorities killed the remaining 8,000 chickens at the farm on Sunday after almost 4,000 birds died from the disease.

Earlier tests had shown the chickens on the farm in Miyazaki prefecture were infected with an H5 subtype of the virus, but further testing was needed to determine whether the virus had the N1 component that would make it the highly pathogenic H5N1 strain or the less lethal H5N2.

Fears over the disease have rippled across Asia, with an Indonesian hospital overwhelmed by human cases of bird flu this week, while the virus is spreading further among flocks in Vietnam and has flared anew in Thailand.

Miyazaki on Japan's southernmost main island of Kyushu is the country's top breeder of chickens, local authorities say. As of Feb. 1, 2006, the number of chickens it was raising for meat totaled 18.4 million birds.

In 2004, Japan had four outbreaks of the H5N1 type strain in poultry between January and March, including an outbreak in Kyoto in western Japan that led to the disposal of about 240,000 chickens and 20 million eggs.