After the death of 23 Asiatic lions over three weeks in the Gir forest of Gujarat, scientists at the Indian Council of Medical Research’s National Institute of Virology (NIV) have confirmed the presence of the Canine Distemper Virus (CDV) in at least five of 24 samples that were tested.
The CDV causes a highly contagious disease in lions, which is also life-threatening in dogs and several wild animals, including wolves, foxes, raccoons, red pandas, ferrets, hyenas, and tigers. The prevalence of this virus and its diversity in the wildlife of India has not been not studied. Only a few reports regarding the detection of CDV in captive wild carnivores are available, which includes the tiger and red panda.
ICMR Director-General Dr Balram Bhargava told The Indian Express that the virus has so far been detected in only five samples from the 24 tested. The institute however, has not ruled out a CDV infection, despite the other blood samples testing negative for the virus. Forest officials have been asked to send appropriate samples to NIV for further investigations.
“We need samples like ocular, nasal and rectal swabs for lab testing,” ICMR officials said.
Laboratory investigations were conducted by NIV using 24 samples collected from twelve lions (three dead, eight under treatment, and one recovered). These samples were collected between September 19 and 24 and included blood in the EDTA, ocular, nasal, rectal swabs, and visceral organs in viral transport medium.
The 24 samples were tested for CDV and Paramyxoviridiae, and five samples were found to be positive for CDV, the report said. On October 2, 22 more blood samples from 22 lions were tested for CDV and Paramyxovirus and found to be negative.
According to a preliminary report by ICMR, a complete genome of CDV was recovered at NIV. “The sequence was compared to available CDV sequences and it was found to be related to East African strains,” the report says.
Officials have also said that existing CDV vaccine should work as a protective intervention for lions during the current viral outbreak. “Vaccination of lions with CDV should be taken up on an urgent basis,” the report says.
The report says it is critical to place the lions in two or three different sanctuaries to prevent the spread of infectious diseases like CDV and protect them from extinction.