Bird flu, or avian influenza, has spread to the forest and protected areas of Himachal Pradesh, Gujarat, and Kerala and infected mostly migratory duck species over the past week, the Union environment ministry has said. In other states, mostly poultry has been impacted.
"The first cases of avian influenza were reported from the Pong Dam in Himachal Pradesh. But following that reports have come from forest areas of Kerala and Gujarat where the affected birds are mostly migratory duck species in forest wetlands," said the ministry's additional director general, Soumitra Dasgupta.
The ministry is trying to get other agencies like the department of fisheries involved in controlling the spread. "We have to see which are the other bird species that have been infected," said Dasgupta.
Dasgupta added an advisory was issued to all chief wildlife wardens on January 3 asking them to keep a strict vigil on the wintering habitats of migratory birds including wetlands for any mortality or outbreak signs.
Bombay Natural History Society (BNHS) director Bivash Pandav said most migratory waterfowl species are known to be carriers of the H5N1 virus (bird flu). "Most recently there have been reports of red junglefowl [contracting the disease]... They are a relatively rugged species. So, it is very surprising that they contracted the virus. The avian influenza virus normally does not jump over to humans but can be easily transmitted from migratory species to domestic birds and has great potential to completely damage our poultry... and even pigs."
Pandav said the possibility of endangered bird species contracting the virus cannot be ruled out. "We have to be extremely watchful and monitor wetlands and other wintering grounds. You cannot catch migratory birds and vaccinate them. All you can do is protect other species like vultures. Precautions must be taken in zoos. This epidemic cannot be taken lightly as the virus mutates and evolves very quickly." Pandav added birders and nature lovers can help in reporting cases of dead or sick birds but they should avoid going close to them.
The ministry's advisory said the affected birds have symptoms such as tremors, diarrhoea, head tilt, and paralysis. The disease spreads quickly causing paralysis and staggering. The advisory asked state chief wildlife wardens to prepare action plans for monitoring migratory birds and for dealing with any emergency.
"Dead birds should be handled with utmost caution and scientific supervision and surveillance should not be restricted to the protected areas alone, but to all such wetlands and habitats that provide grounds to the migrating birds and to areas where there is a possibility of interaction of migratory birds and poultry such as backyard poultry."
The forest department staff has been asked to use protective gear like rubber gloves, eye gear, or face shield, and to disinfect hands and surfaces and take antiviral drugs. The virus is much more difficult to inactivate if it is encrusted in organic material such as faeces or soil.
Experts say bird flu has various strains with H5N1 being the worst as it can jump from birds to mammals. H5N1 also spreads through fomites or infected surfaces. So, surfaces interacting with infected bird species can also spread the virus.
Ornithologist Asad Rahmani said most domestic birds are kept away from wild birds but as domesticated ducks feed in the same paddy fields where wild ducks also feed, there are chances that disease may transmit either way. "Similarly, poultry farms are spread all over India, sometimes near to areas where wild birds are found. Hence, poultry farm birds are also susceptible to get the avian flu from wild birds [and vice versa]."