Bird flu appears again in heavily populated region of India

Another outbreak of deadly bird flu in India has put health authorities on high alert following the deaths of thousands of chickens.

This latest confirmed outbreak of the H5N1 virus is the fourth to occur in the eastern West Bengal state in the past year.

West Bengal Animal Resources Development Minister Anisur Rahaman says several thousands of poultry have died in Darjeeling's hilly Mathigarah villages of Siliguri and Pubang and samples taken from the dead poultry have tested positive for bird flu.

A further 20,000 infected birds are being culled by 30 culling teams sent to the affected areas but beyond the 5 km radius of the two epicentres there are no restrictions on the selling and consumption of birds and poultry products.

In 2008 the West Bengal state authorities were forced to slaughter five million poultry to control the virus during India's worst bird flu outbreak when the virus spread to 14 of the 19 districts in the state.

West Bengal is heavily populated and has more than 80 million people but India has not had any reported human cases of the deadly H5N1 strain of the virus to date.

In December officials in the northeast state of Assam culled 250,000 chickens in order to control the spread of the deadly infection, which had sparked fears of a human case after a number of people were reportedly sick.

Bird flu first appeared in India in 2006 and it has resurfaced from time to time causing millions of chicken and ducks to be culled to contain the virus.

Experts have been warning since 2003 that the H5N1 virus might mutate or combine with the highly contagious seasonal influenza virus and spark a pandemic that could kill millions of people across the world.

According to the World Health Organisation, H5N1 bird flu has infected more than 390 people in 15 countries and killed at least 247 of them since the virus resurfaced in Asia in 2003.