The spread of bird flu among poultry has become "alarming" in Bangladesh as three more districts reported outbreaks at the weekend, leaving almost half the nation affected, an official said Sunday.
More than 10,000 birds were slaughtered in north and south Bangladesh late Saturday as part of a continued massive cull to contain the deadly H5N1 virus, the senior government science adviser, who declined to be named, said.
"On Saturday alone we had culls at 18 farms. And this morning we have already 10 more farms affected with the disease," he said.
Since Bangladesh's first bird flu outbreak in February last year, the disease has been detected in 29 out of the country's 64 districts, prompting authorities to slaughter at least 360,000 birds.
The officials said the situation in the impoverished country of 144 million was so wide in scope that even wild crows had been apparently infected.
"It is an alarming situation. Hundreds of crows are dying every day across the country due to the bird flu. The government should make it an emergency health issue," the adviser said.
"Farmers in some villages are throwing away dead chickens in canals and ponds, spreading the disease without knowing it," he added.
Experts had said earlier this month that the situation was far worse than initial government claims because farmers failed to report many cases.
The United Nations' Food and Agriculture Organisation said on Thursday Bangladesh needed house-to-house surveillance to fight the spread of bird flu because the situation had worsened and was "posing a danger to public health".
The Bangladesh poultry industry produces about 220 million chickens and 37 million ducks annually, one of the world's largest populations.
Bangladesh is the world's most densely populated country, with nearly 1,000 people per square kilometre (2,600 per square mile).
Experts fear bird flu could mutate and develop into a form that can easily spread from human to human.