"Our Vegan Campaign Coordinator Rohini Kamath had written to the director of WB Animal Husbandry in June, warning of an outbreak of bird flu if best husbandry practices were not ensured in poultry farms and supply chains. We did not get any response," PeTA official N G Jayasimha said.

Culling was the only option under the present situation, but it was not being done as per guidelines of the WHO and the Royal Society for Prevention of Cruelty to Animals, thus keeping the possibility open for the virus to spread, he said.

Displaying shocking video footage of poultry management shot by undercover PETA activists, he said the deadly H5N1 virus could spread very fast because of intensive confinement of the birds.

"Bird flu can be caught by humans who handle infected birds and experts fear that the virus will eventually mutate into a form that is transmissible among humans, setting off a worldwide pandemic," the PETA official said.

Jayasimha said the problem with West Bengal and the North Eastern states is that these states mostly have backyard farms where husbandry practices were far from healthy.