Nipah Virus in India: ICMR-NIV team finds Nipah Virus antibodies in bats from Mahabaleshwar cave; Details

In India, large fruit-eating bats called Pteropus medius bats are thought to be the cause for the virus. (Representational image)

Nipah virus: The Indian Council of Medical Research (ICMR)- National Institute of Virology conducted a cross-sectional survey to study Nipah Virus (NiV) and its prevalence in the country’s bats. During the survey, samples of some species of bats found in a cave in Maharashtra’s Mahabaleshwar have been picked up, in which antibodies against NiV are present, according to a report in IE. The development is significant because NiV has been included in the priority list of top 10 pathogens identified by the WHO. India has till now seen four different outbreaks of NiV.

While the first instance of NiV infection had been reported in West Bengal’s Siliguri in 2001, the second episode was reported from the same state’s Nadia in 2007. The report added that NiV antibodies were present in Assam’s Dubri district and in West Bengal’s Cooch Behar, both of which are located close to India’s border with Bangladesh. A third outbreak of the virus in 2018 in Kerala’s Kozhikode was reported in which 18 people died. Another wave of the virus also struck Kerala in 2019 as well.

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A study conducted in 2018 had said that many countries in South East Asia, including some states in India as well, could be identified as hotspots for the disease caused by Nipah Virus.

In India, large fruit-eating bats called Pteropus medius bats are thought to be the cause for the virus, as both the RNA of NiV as well as its antibodies were found to be present in the samples collected from these bats during outbreaks. However, it is important to note that studies on other bat species being potential reservoirs of the virus have not been conducted extensively in India.

The study, called “Detection of possible Nipah virus infection in Rousettus leschenaultii and Pipistrellus Pipistrellus bats in Maharashtra, India”, has been published in Journal of Infection and Public Health. For this, two species of bats, viz “Rousettus leschenaultii” which are medium-sized fruit-eating bats and “Pipistrellus pipistrellus” which are tiny insectivorous bats, were trapped from a Mahabaleshwar cave in March last year and then anaesthetised onsite. Following this, blood, rectal and throat swab samples were collected from these bats.

The team found the presence of NiV RNA to be present in a number of samples, and the same was the case for antibodies. However, one bat of each of the two species was found to have both the RNA and the antibodies, the report added, citing NIV scientist Dr Pragya Yadav as saying that this marked the first demonstration of the possibility of NiV infection in R leschenaultii bats in the country.

Researchers have now said that this finding warrants a further study into this aspect as no conclusion can be reached from the current survey considering the small screening sample of bats.