'Manipur bird flu unsafe for humans'

NEW DELHI: The bird flu virus, that was detected in Manipur in July, was the highly pathogenic Qinghai strain, which is capable of infecting humans.

Genetic sequencing of the virus, isolated from the small poultry farm at Chingmeirong in Imphal East district, which reported the outbreak, has shown it to be similar to the virus that originated in China’s mid-western province of Qinghai.

The Qinghai strain, which has now reached at least 50 countries, has a mutation that helps the virus grow at temperatures found in human noses, which are cooler than the insides of the bird's intestines.

Scientists at the High-Security Animal Disease Laboratory in Bhopal, who carried out the genetic sequencing of the genes HA and NA of the virus, isolated from Manipur, told TOI that "the cleavage site of the genes in the virus had over six basic amino acids" which determined "its tremendous toxicity".

According to Dr H K Pradhan, former chief of the laboratory, the higher the content of amino acid, the more lethal the virus. He said that the eight virus strains isolated from Manipur were so lethal that 99% mortality was recorded within 48 hours of the virus being injected into test birds in the lab.

These revelations come a day before New Delhi hosts the international ministerial conference on avian and pandemic influenza, to be attended, among others, by the heads of WHO and FAO.

Dr Pradhan said: "We now know that the virus was of clade 2.2 variety and came from a mixed migratory bird group. During sequencing, it was seen that the cleavage site had over six basic amino acids. Scientifically, any virus having over two basic amino acids is pathogenic. Amino acids help the virus in entering the system inside the bird’s body, killing it instantly."

The scientists, however, failed to ascertain whether the virus came from China, Bangladesh or Myanmar - all three countries recorded outbreaks just before the virus hit India.

However, the team said that the outbreak might have been the result of a local bird getting infected by coming in contact with virus-carrying bird droppings or feathers. "After completing the genetic sequencing of a virus, the scientists post their findings in a public gene bank of the American National Center for Biotechnology Information. However, Bangladesh and Myanmar have not done so. We, therefore, couldn’t match our samples and pinpoint their origin," Pradhan said.

An animal husbandry department official added: "Bird flu is usually spread by migrating fowl and domestic birds are susceptible to infection. But because the virus was isolated from just one farm, we believe it could be because a local bird came in contact with the faecal dropping or infected feathers of migratory birds near the farm."

Source: timesofindia.indiatimes.com