March 19, 2004

Japan, Korea Bird Flu Virus Identical

Japanese scientists have discovered that the DNA base sequences of the bird flu virus in Japan and South Korea are virtually identical, indicating migratory birds may have carried the virus from each other.

Japan's National Institute of Animal Health has found that more than 99 percent of the DNA base sequences of the virus from infected birds from Japanese sites are identical to the sequence in one sample obtained from South Korea in March.

This increases the possibility that the virus was transmitted by migratory birds such as wild ducks. The four infected Japanese sites are all located in western and southwestern parts of the country relatively close to the Korean Peninsula.

The highly virulent H5N1 strain of the virus appeared in South Korea last December and then turned up in Japan in January. It mainly infected chickens and no human infections have been reported in either country.

The institute has already determined three affected poultry farms in west Japan's Yamaguchi and Kyoto prefectures and one household in southwest Japan's Oita Prefecture was infected by virtually the same strain of the virus.