Health officials on Tuesday confirmed bird flu disease in some districts of West Bengal and said that culling of chickens would start immediately.
Laboratory tests showed that it is a strain of H5N1, a deadly virus which can also affects humans.
Influenza A virus subtype H5N1, also known as A(H5N1) or H5N1, is a subtype of the Influenza A virus which can cause illness in humans and many other animal species.
Another bird flu confirmed state, Assam also struggling to control the deadly disease. Some humans also reported fever and respiratory infections in Assam and health officials closely examining these people.
Health officials in Assam have already finished culling of more than 300,000 chickens.