Bird flu spreads to 10 states, govt says human threat low
Bird flu spread to 10 states on Monday with Delhi, Maharashtra and Uttarakhand confirming the viral outbreak, which experts said would be difficult to control because a large number of birds in the wild had been infected.
The Central government moved to ease concerns of the infection spreading to humans through contaminated meat or chicken, saying that in India the disease had been spread mainly by migratory birds and added that the secondary spread to poultry birds had occurred only at a few places.
“There are no scientific reports on transmission of bird flu to humans and consumers should not be scared,” minister for fisheries, animal husbandry and dairy Giriraj Singh told reporters on Monday, asking the states not to close wholesale markets or restrict the sale of poultry products.
Delhi, Maharashtra and Uttarakhand joined Himachal Pradesh , where close to 4,000 migratory birds have died in Pong Dam, Madhya Pradesh, Rajasthan, Uttar Pradesh, Gujarat and Haryana in confirming bird flu cases.
While transmission of the virus to humans is rare, it easily spreads among birds through droppings. “The entire water body gets infected with the virus, a reason for so many birds dying in Pong Dam in Himachal. Also, it spreads the disease from one species to another,” said Suresh Kumar, a scientist with the Wildlife Institute of India and migratory bird expert.
Migratory birds reach India at wintering sites through the Central Asian flyway, which extends from the Artic in the north to Maldives in the south and from central China in the east to eastern Europe in the west. It is one of the eight major migratory bird flyways and least studied among all, said a report in Birdlife International, a global partnership of non-government organisations devoted to avian conservation.
Asad Rahmani, former director of the Bombay Natural History Society (BNHS), said the birds from Central Asia, China, Mongolia and Siberia cover more than 5,000 kms to reach hundreds of wintering sites in the Indian subcontinent and some of them even fly to Tamil Nadu, Kerala and Sri Lanka.
Close to 90% of the 370 identified species in the CAF reach the Indian subcontinent and spread across the country. “You can find Bar-headed Goose in Kaziranga and Pong Dam. They may enter India through two ends of Tibetan plateau. They are of same species but represent different populations,” Kumar said.
Rahmani said that some of these migratory birds may be carriers of bird flu although they may not perish. Not much research has been done on bird diseases, and it would not be possible to say which birds carry which strain of bird flu, he added.
Testing by Bhopal-based National Institute of High Security Animal Diseases (NIHSAD) indicates that both the strains of bird flu came from migratory birds. H5N8, a sub-type of avian influenza found in poultry and wild animals, has been found in crows in Rajasthan, Uttarkand and Madhya Prades; the strain came from migratory birds. The other strain is H5N1, found in ducks in Kerala and the Bar-headed Goose in Himachal. While H5N8 transmission to humans is not known, there have been cases of H5N1 transmission to humans, although rare.
“There is no way one can control bird flu in wild birds,” Kumar said, noting that it spreads from droppings in water bodies that are impossible to clean. “Poultry bird flu is easier to contain as all birds can be culled and cleaning operations can be completed in 90 days.”
That could be a probable reason that Kerala and Haryana, where the virus was reported in poultry, were able to control bird flu and not Rajasthan, Himachal and Madhya Pradesh, where it was present in birds in the wild.
On Monday, Madhya Pradesh’s animal husbandry director Dr RK Rokde said the latest reports had confirmed bird flu in pigeons, sparrows and herons, but morbidity was the highest among crows.
“As of now, 1,300 birds have died of bird flu in about 35 districts of MP and spread of avian influenza has been confirmed in 18 districts,” said Rokde.
In Rajasthan, bird flu reached Jaipur zoo, causing the death of three ducks and a black stork, forcing the authorities to close the bird section. Fowl deaths had earlier been reported from Kanpur zoo in Uttar Pradesh. The total bird deaths because of bird flu in a week doubled to 3,321 on Monday with the spread of aviation influenza to 15 of 33 districts of Rajasthan. Most of the birds that perished were crows.
Apart from Sanjay Lake in Delhi, bird flu was confirmed in wild birds, mostly crows, in Maharashtra and Uttarakhand. An outbreak of avian influenza was reported among poultry in Parbhani district of Maharashtra while bird flu in crows was confirmed in Mumbai, Thane, Dapoli and Beed, officials said.
In Uttarkhand, bird flu in crows has been confirmed from Pauri Gharwal district. In Gujarat, bird flu cases have been confirmed in crows in Surat and Vadodara districts, officials said.
Rahmani said the only way to control bird flu infection from migratory birds was through satellite-based monitoring of major bird species and rapid information sharing between 30 countries on the Central Asian Flyway. Kumar said nine flagship migratory species including the Amur Falcon, Common Crane and Black Kite are monitored under an environment ministry’s programme.
(With inputs from state bureaus and agencies)