With ducks dying in large numbers in Kuttanad and upper Kuttanad, samples of affected birds will be sent to the National Institute of High-Security Animal Diseases (NIHSAD), Bhopal, for analysis.
According to authorities, around 22,000 ducks died in the past week or so. Majority of the dead ducks belonged to two farmers in Thalavady and Pallippad grama panchayats.
The decision to send samples to NIHSAD was taken after tests conducted at a virology lab in Thiruvananthapuram was inconclusive.
Officials said that necropsy had found bacterial, fungal infections, ascites, and liver, heart and lung diseases in ducks.
“The exact cause of mass deaths of ducks is yet to be ascertained. The initial tests came back inconclusive. Tests have revealed mixed infections in ducks. Bacterial/fungal infections or other diseases found in the dead ducks could be secondary infections caused as a result of a primary virus infection. Tests to be conducted at the lab in Bhopal will help identify the primary cause of deaths,” said an official with the Animal Husbandry Department.
Santhosh Kumar, District Animal Husbandry Officer, said that they expected to receive the results from NIHSAD in a couple of days.
“Medicines remain ineffective. But the disease is largely confined to two places and there are no signs of it being spread to more areas. At present, we cannot say it is a highly pathogenic strain. We will have to wait for results from Bhopal for any confirmation,” Dr. Santhosh Kumar said.
On Monday, a team led by Priya P.M., associate professor, Department of Veterinary Microbiology, College of Veterinary and Animal Sciences, Mannuthy, visited Kuttanad and collected samples for testing. The test results are expected in the coming days.
Earlier in February, a large number of ducks had died at Pavukkaram, near Mannar, due to a bacterial infection. Samples examined at the Avian Disease Diagnostic Laboratory at Thiruvalla then revealed that the ducks had been infected with Riemerella anatipestifer, an antibiotic-resistant bacteria.
In September 2018, a large number of ducks succumbed to bacterial infection in upper Kuttanad. Before that bird flu (avian influenza), caused by the H5N8 virus, was detected among ducks in Kuttanad in 2016. In 2014, thousands of ducks died/culled in the region following a highly infectious bird flu outbreak caused by H5N1 virus.