Anti-bird flu warriors grope in the dark

The confirmation of avian influenza among the birds housed at Central Poultry Development Organisation & Training Institute (CPDOTI) in Hesaraghatta near here has only worsened the situation, with fears of it leading to a further outbreak among birds and — in a more scary scenario — among humans too.

This is because while confirming that the samples of chickens, ducks and emus had tested positive for avian influenza, the scientists at the High Security Animal Disease Laboratory (HSADL) in Bhopal have not been able to identify precisely whether the virus infecting the CPDOTI birds is a mutation or not. Nor have they been able to determine how rapidly this virus can infect humans, or even the pace of disease spread among birds.

The situation is scary because as per scientists at HSADL who preferred to remain anonymous, a year ago a dangerous mutation of the H5N1 virus (the virus that causes avian flu) had occurred in July-August 2011.

There are three series type of viruses that cause avian flu -- H5, H7 and H9. Of these H5 is the most infectious, and known to have caused deaths among humans too.

The H5N1 virus with the mutation, identified only as H5N1-2.3.2.1, was detected in North and Central Vietnam. Last year, a chief veterinary officer of Food and Agricultural Organisation, had identified poultry sector in India among those of neighbouring nations to be at extreme risk of being hit by this mutant virus.

No one in Bangalore or at HSADL in Bhopal know for sure whether the infecting virus now is the basic H5N1 virus, the deadly mutated H5N1-2.3.2.1 virus, or a deadlier mutation than that.

What is further worrying is this: The possibility of it being a mutant would mean that a range of antibodies used for developing human vaccines (in case required) would be rendered useless. This, because most human vaccines for H5N1 virus have been derived from 2004 strains of the virus, much before the deadly mutations were recorded.

The experts also point to another worrying scenario. The H5N1-2.3.2.1 virus was found to become more and more dominant with such vaccines against it -- a role-reversal compared to vaccines formed with weaker germs strengthening blood cells that fight them.

CPDOTI scientists are tight-lipped about how they are planning to deal with the situation. However, experts at HSADL said they would be groping in the dark and only make matters worse if they had to try and tackle the virus with the existing vaccines. “And it could turn disastrous if the virus that has attacked the birds now is a further mutated one,” said one of the scientists.

For now, preventive and precautionary measures seem the only hope for Bangalore -- and for that matter, Karnataka and entire India.