Even as laboratory tests have confirmed that bird flu has spread to new blocks of Birbhum, Murshidabad and Hooghly districts of West Bengal, state animal husbandry department officials said on Thursday that more than 80 per cent of culling was completed.
A report from the High Security Animal Disease Laboratory (HSADL) in Bhopal on Wednesday said samples from Suri I in Birbhum, Raghunathganj II in Murshidabad and Chanditala II in Hooghly had tested positive for avian influenza.
Hooghly District Magistrate Vinod Kumar confirmed the outbreak at Hutpur village of the district, which is barely 20 kms from Kolkata. The eastern metropolis is now hemmed by areas affected by bird flu.
The HSADL is yet to confirm the report of bird flu spreading to Baduria in Kolkata's adjoining North 24 Parganas district but the state government has already said the deadly H5N1 strain has been found in samples taken from there.
Officials said the number of birds culled in the 13 affected districts of West Bengal had crossed 2.3 million and another 500,000 poultry would have to be culled.
However, no human infection has been detected so far in the state.
Officials said that among the 1.6 million people surveyed, teams of healthcare personnel have detected 3,700 people with signs of upper respiratory infection such as cold, cough and fever. Only 28 have had a history of exposure to poultry.
However, none of these people had symptoms of avian influenza like lung infection, breathlessness or lung patches visible on X-ray.
But reports of untoward incidents poured in from various parts of the state.
Villagers of Bajitpur, Parchandrahat and Chattaparulia in Birbhum's Mayureswar-I block, which is affected by bird flu, reportedly exhumed culled poultry birds on Monday and went to the local panchayat office with the birds demanding interim relief of Rs 500 for each family as announced by the state government.
Reports said the villagers brought the culled birds to prove that they are among the affected families. The culled birds were again buried in the trenches at the intervention of the police, who issued a stern warning on Wednesday that anyone found exhuming dead birds would be arrested.
Bird flu was confirmed in West Bengal on January 15. The affected districts are South 24 Parganas, Howrah, Hooghly, Birbhum, South Dinajpur, Murshidabad, Nadia, Burdwan, Bankura, Malda, Cooch Behar, Purulia and West Midnapore.
The World Health Organisation (WHO) has described the bird flu outbreak in West Bengal as "serious".
In neighbouring Bangladesh, which shares a long border with West Bengal, bird flu has affected 29 out of 64 districts in the country. Bangladesh authorities declared the outbreak on January 3.