A genetic analysis confirmed the presence of a highly pathogenic strain of avian influenza in both prefectures. A total of 510,000 chickens will be culled in Okayama prefecture and 1.04 million in the prefecture of Ibaraki.
A quarantine has been introduced for the transportation of chickens and eggs within a radius of 3 kilometers (1.8 miles) around farms, where the virus was registered. In addition, the export of chickens and eggs outside the 10-kilometer zone was also prohibited.
Since the beginning of fall, Japan has registered bird flu outbreaks in the prefectures of Okayama and Kagawa, as well as on the island of Hokkaido. A total of 1.89 million chickens have been culled over the past month, which is similar to the number of birds culled over the last year.
Bird flu is a highly contagious virus that can cause influenza in birds and result in their deaths. In a period from the fall 2020 to spring 2021, Japan suffered the largest avian influenza outbreak in the country's history. The virus affected more than a third of prefectures, with about 10 million chickens culled in more than 50 farms.