The Indian Government used the drug Tamiflu to avert the bird flu outbreak when the deadly virus H5N1 struck the country in February 2006.
Scientists at the High Security Animal Disease Laboratory in Bhopal carried out DNA sequencing and genetic analysis of virus collected from Jalgaon and Navapur. The findings showed that the virus was sensitive to Tamiflu due the different types of amino acids like glutamic acid, asparigine, histidine and arvinone present in it.
This helped in the prevention of a possible transmission of the lethal virus from birds to humans.
Scientists B Patnaik and C Tosh, who have completed sequencing the genes HA1 and HA2 of the virus and studying the 10 proteins, specially HA and NA present in the virus, said, "Timely administering of Tamiflu to those who were quarantined on suspicions of having been in contact with H5N1 virus infected birds, helped us avert the transmission of the virus to humans. DNA analysis of the virus has shown it to be highly sensitive to Tamiflu".
Lab chief H K Pradhan said, "Some countries including Vietnam have reported that the virus circulating there is resistant to Tamiflu making its containment even more difficult. Our DNA tests, conducted of the HA, NA, NS1 and PV2 proteins, showed the virus that hit India was capable of infecting mammals, including humans. Therefore, a Tamiflu resistant virus would have resulted in people being infected by the bird flu virus easily, ultimately resulting in their mortality."
According to the scientists, the strain of virus that hit India, particularly the one at Navapur was a mutated one and had undergone reassortment in Turkey. Migratory birds carried the virus strain that originated in Qinghai (central China) to Turkey, where the virus underwent mutation and got assorted with the Vietnamese strain. This re-assorted virus strain was brought to India by migratory birds. This kind of re-assorted virus attack has not been reported for the past 4 years in any country.
"The influenza virus mutates quickly. So did the H5N1 virus that came to India. Turkey is one of the few countries where both the Chinese and Vietnamese strain have been found.
"The virus that was found in Navapur was a mixed strain. That's why we believe the mixing happened in Turkey. While the NA was the Vietnamese type, the HA was Chinese," Pradhan added.