Control of an outbreak of highly pathogenic avian influenza, caused by the virus sub-type H5N1, in Japan in 2004.

An outbreak of highly pathogenic avian influenza (HPAI), caused by the virus sub-type H5N1, occurred at four premises in three prefectures in Japan during January and March 2004. As a result, 274,654 poultry died or were slaughtered. This was the first outbreak of HPAI in Japan since 1925. (The earlier outbreak was caused by H7N7.) The disease was successfully eradicated within three-and-a-half months, following an eradication campaign that included depopulating the affected premises, implementing movement controls and intensive surveillance. Control measures were conducted in accordance with the National Manual of HPAI Control. However, during the eradication campaign, some key issues arose, such as delays in notification by the affected farmers. As a result of these experiences, the relevant laws and HPAI Control Manual have been appropriately revised.