Bird deaths in Rajasthan due to botulism: IVRI report

BAREILLY The Indian Veterinary Research Institute (IVRI) has confirmed that the death of thousands of migratory birds at Sambhar Lake of Rajasthan was due to avian botulism, a neuromuscular illness in birds.

“We carried out lab tests on the samples we received from Rajasthan authorities. The tests confirmed that the deaths were due to avian botulism,” said Dr Raj Kumar Singh, IVRI director.

The illness is caused by a toxin that is produced by the bacterium clostridium botulinum, said scientists.

Located 80 km southwest of Jaipur, Sambhar Lake is recognised as a wetland of international importance and a key wintering area for thousands of birds.

The IVRI director said there were several factors, which could lead to the outbreak of the toxin-producing bacteria, which occurs when there are large amounts of decaying plant or animal materials, which are also anaerobic and there is a fall in water levels.

“These bacteria are harmless initially until the environmental factors and anaerobic conditions prompt them to germinate and begin the vegetative growth of the toxin-producing bacterial cells,” he said.

Dr Singh said that a report had been sent to the Rajasthan authorities.

Earlier, experts at the National Institute of High Security Animal Diseases (NIHSAD) in Bhopal had suspected avian botulism as the reason behind the deaths, but samples were sent to the IVRI Bareilly to confirm the same.

More than 18,000 birds have died in Rajasthan’s Sambhar Lake, the largest inland salt lake in India since November 10, raising concern of environmentalists and ornithologists.

The lake is among the eight worst-rated wetlands in the country when it comes to ecosystem management, according to a draft report prepared by the environment ministry in consultation with several independent experts.