The samples were the sent to the CDC in January because the virus could not be typed in Bangladesh, said a senior official in the World Health Organisation (WHO). The United Nations agency took several months for testing to be completed before officially announcing the results.

“The H5N1 virus was first detected in Bangladesh in March last year and since then the authorities have culled around 2 million chickens and destroyed millions of eggs,” said an official. Fifty of the country’s 64 districts were affected and 40 per cent of its poultry farms were closed at the peak of the outbreaks, causing “losses of about 45 billion taka ($650 million) for the growing poultry sector, which accounts for 1.6 percent of the impoverished nation’s gross domestic product,” said a WHO spokesperson.

Experts fear the H5N1 strain could mutate or combine with the highly contagious seasonal influenza virus and spark a pandemic, especially in countries where people live in close proximity to backyard poultry. The human case in Bangladesh has put the Indian Government on its toes. The Department of Animal Husbandry has recently attributed the spread of the virus to illegal smuggling of poultry from Bangladesh to neighbouring states like Tripura. The country has also been suspected of being the source of past outbreaks in West Bengal and Manipur. Although the border has been sealed, the effectiveness of the measure is still open to question.

Earlier last month, the Foreign Secretary summoned the high commissioner of Bangladesh for not sharing vital information regarding the virus and also wrote to the Indian high commissioner in Dhaka asking him to intervene. Bangladesh has so far denied the Indian Government information about the gene sequencing of the virus. According to a WHO report released in April, of the 382 people who have contracted bird flu since 2003, 241 have died. An emergency meeting to address the issue has been called by the Ministry of Health and Family Welfare on June 3.