Multi-institutional team tracks virus behind India’s lumpy skin cattle

Bengaluru: A multi-institutional team has provided critical insights into the evolution and origins of the virus strains fueling lumpy skin cattle disease outbreak, the Indian Institute of Science (IISc) has said.

In May 2022, cattle across India began dying of a mysterious illness.

Since then, about 1,00,000 cows have lost their lives to a devastating outbreak of what scientists have identified as lumpy skin disease, Bengaluru-based IISc said on Tuesday in a press release.

“It was a calamity in some ways-a national emergency,” said Utpal Tatu, Professor in the Department of Biochemistry, IISc. Tatu is part of a multi-institutional team that decided to probe the cause of the outbreak. Their study was published in ‘BMC Genomics’, the press release issued by IISc said.

A viral infection caused by the Lumpy Skin Disease Virus (LSDV), it is transmitted by insects like flies and mosquitoes. It causes fever and skin nodules and can be fatal for cattle.

LSDV was first found in Zambia in 1931 and remained confined to the Sub-African region until 1989, after which it started spreading to the Middle East, Russia and other southeast European nations, before spreading to South Asia.

There have been two major outbreaks of this disease in India, the first in 2019 and a more severe outbreak in 2022, infecting more than two million cows, the release said.

To investigate the current outbreak, the team collected skin nodules, blood and nasal swabs from infected cattle in various states including Gujarat, Maharashtra, Rajasthan and Karnataka, in collaboration with veterinary institutes. They performed advanced whole-genome sequencing of DNA extracted from 22 samples.

Their genomic analysis revealed two distinct LSDV variants circulating in India -- one with a low number of genetic variations and another with a high number of genetic variations. The sequence with fewer variations was genetically similar to the 2019 Ranchi and 2020 Hyderabad strains that were sequenced previously. The samples with high variations, however, turned out to be similar to LSDV strains from an outbreak in Russia in 2015.

Kumar said that there are no previous reports of such highly varied LSDV strains in India.