KOLKATA: Workers sprayed roads and markets in Kolkata with disinfectants and culled thousands of birds as authorities in eastern India battled to stop an outbreak of bird flu in poultry reaching the crowded city.

Bird flu has spread to 13 of West Bengal’s 19 districts and authorities in the communist-ruled state said they were culling sick chickens in a private farm about an hour’s drive from Kolkata, one of India’s biggest cities.

“We are not taking chances as the farm reported bird deaths and preliminary tests suggest bird flu,” Anisur Rahaman, the state’s animal resources minister said.

India’s bird-flu hit state of West Bengal appealed to New Delhi to allow the United States and China to come to its aid in battling the disease, an official said on Wednesday.

“I have urged the chief minister to have talks with the federal government so that we can approach the United States and China for help,” Rahaman said. Both countries have already offered to assist the state, local reports have said.

The United States has offered technical help to the surveillance teams as well as protection gear and other equipment, the Express report said.

Over 2 million birds have already been culled, but authorities now say they will slaughter thousands of more birds. They will also ban rearing backyard poultry in infected districts for at least three months.

India was checking hundreds of villagers and health workers for possible symptoms of bird flu, officials said.

Experts fear the H5N1 strain could mutate into a form easily transmitted from person to person, leading to a pandemic, but there have been no reported human infections in India yet.

The World Health Organisation has said it is India’s most serious outbreak of bird flu. Authorities say a major problem is that most poultry in the state of 80 million people are raised in backyards and some farmers have resorted to hiding their birds from culling crews.

Farmers raise poultry to earn a little extra money or to ensure a reliable source of protein. Many also say compensation of $1 a bird is too low.

Authorities have stepped up efforts to ring-fence the outbreak to keep it spreading to major urban areas in West Bengal and to stop the virus crossing into other states. Authorities banned selling chicken in Kolkata’s Salt Lake area, eastern India’s IT hub that houses offices of leading firms such as Cognizant Technology Solutions Corp and IBM. They were also disinfecting roads and trucks linking Kolkata to neighbouring districts.

“We are trying to minimise the chances of the virus hitting Kolkata,” Deb Dwaipayan Chattopadhyay, a senior health official, said.

India, the world’s second largest producer of eggs, has seen a fall of roughly 50 per cent in egg sales abroad, but the losses, some $20 million, is small given India’s trillion dollar economy. Local poultry markets have also suffered.

West Bengal accounts for about 15 per cent of India’s total chicken consumption.

Health workers in Kolkata were also keeping watch on street markets, following reports of sick birds being smuggled into the city. Authorities used loudspeakers and distributed leaflets in villages, asking people not eat infected poultry or eat animals dying suddenly. Hundreds of goats, pigs and wild birds have died since the H5N1—Agencies