A visible rise in the number of crow deaths in many parts of the State, including Kolkata, for months and, near lack of communication from State administration about the reasons involved, has set the grapevine abuzz about a probable outbreak of another round of bird flu in West Bengal.
Avian influenza or bird flu was last reported in Nadia district of West Bengal in September 2011. Outbreak of the disease was recently reported in the North Eastern States of Tripura and Meghalaya. In the Eastern region Odisha, reported outbreak in two districts and conducted second phase of culling operations in Mayurbhanj this month.
Incidentally, Odisha as well as Jharkhand, both bordering West Bengal, reported a large number of crow deaths in recent months, leading to widespread panic about outbreak of the disease.
Though crows are not considered to be carriers of the disease; available information suggests that large billed crows (Corvus macrorhynchos) commonly called jungle crows were found to have been infected by the virus during the 2004 outbreak in Japan. Jungle crow (though a range of subspecies) is commonly available in India and large part of Asia through a range of subspecies.
However, senior officials in the Bhopal-based Indian Veterinary Research Institute confirm that death toll of crows, as well as other birds, may rise for a variety of reasons, including cold.
Though the unusual rise in the number of crow deaths in the city was first reported in local media nearly two months ago, administrative response was noticed when Kolkata Municipal Corporation collected carcasses and sent them for testing at the city-based Regional Disease Diagnostic Laboratory on January 28.
Since then there is hardly any information available with the State administration on the issue. While sources in the State health department cite non-availability of report, Mr Atin Ghosh, Mayor-in-council (Health) and Dr Gopal Chakraborty, joint director of animal husbandry department, are unaware of any such development (collecting samples and testing).
“We are yet to receive the laboratory report on the cause of death (of crows),” Dr Dipankar Maji, nodal officer for Integrated Disease Surveillance Project (Bengal), told Business Line. He is in charge of keeping the Centre updated on any health-related issues.
According to Dr Maji, clinical examination suggests that there was no outbreak of bird flu and the same was conveyed to the Union government.