Researchers find Nipah virus in two bat species in Mahabaleshwar: Reports

Researchers of the National Institute of Virology have found the presence of Nipah virus (NiV) and antibodies against it in two species of bats from a cave in Mahabaleshwar, Maharashtra for the first time.

The researchers trapped Rousettus leschenaultii (medium-sized fruit-eating bats) and Pipistrellus pipistrellus (tiny insectivorous bats) from a cave in Mahabaleshwar in March 2020 to conduct the study.

The study, titled ‘Detection of possible Nipah virus infection in Rousettus leschenaultii and Pipistrellus Pipistrellus bats in Maharashtra, India’ is published in the Journal of Infection and Public Health.

From the anaesthetised bats, blood, throat and rectal swab samples were collected on-site and later, a necropsy was conducted on 10 bats of each species at the Indian Council of Medical Research-National Institute of Virology (ICMR-NIV), Pune.

The samples of one bat of each R leschenaultii and P pipistrellus species tested positive for NiV RNA and anti-NiV IgG antibodies, while only antibodies were found in several other samples.

Dr Pragya Yadav, scientist and one of the authors, told TOI that this is the first report of NiV infection in bats of Maharashtra.

The presence of NiV RNA and antibodies were first detected in large fruit-eating bats called Pteropus medius bats. As the roosting and breeding habitats of R leschenaultii bats vary from previously-detected Pteropus medius bats, more research in both bats and humans can help in understanding the presence of the Nipah virus in Maharashtra.

“The roost which was sampled was age-old and the virus might have been circulating at low levels and not detected during earlier studies,” Yadav told TOI. Alternatively, R leschenaultii bats could have been introduced to the virus from Pteropus medius bats as both share the same fruit trees.

The World Health Organisation (WHO) has categorised NiV as one of the top 10 priority-list pathogens. Until now, four outbreaks of the Nipah virus has occurred in India with CFR ranging from 65 per cent to 100 per cent.

The first outbreak of the Nipah virus took place in Siliguri district, West Bengal in 2001, followed by an outbreak in Bengal’s Nadia district in 2007. Later, the third and fourth outbreaks took place in Kerala’s Kozhikode district in 2018 and 2019.