Kerala: We need to get database on bats ready, says expert

KOCHI: Though it has been suggested that the same species of fruit bats (Pteropus medius) that caused the Nipah outbreak in 2018 could have caused the latest outbreak as well, an international collaborative study on “Prioritizing surveillance of Nipah virus in India” published in the journal “PLOS neglected tropical diseases” has found that in addition to seven species in Kerala that were previously identified as Nipah virus seropositive, four more bat species have a trait similarity with the known Nipah virus-seropositive species in the state.“While we don’t have conclusive evidence for lack of a database, the recommendation was that we should do PCR tests on all the species, as all the present sampling and tests have been done on bats outside India. The only test that has been done was on the fruit bat in 2018. Now, we know 11 species are in Kerala. The aim is not to create panic, but we need to get the database on bats ready for our own use because of the latest round of attack,” said P O Nameer, professor & head, department of Wildlife Sciences & Centre for Wildlife Studies, College of Forestry, Kerala Agricultural University, who collaborated with international experts for the study.To provide guidance for sampling bats in India and epidemiologic studies looking for animal exposures associated with Nipah virus spillovers in Kerala, the scientists searched the literature for records of studies of Nipah virus and Henipaviruses in bat species known to occur in Asia, Australia, and Oceana.He and his team of students had developed a mobile app called Kerala Bat Map which aimed to find the bat breeding sites in Kerala and map the roosting sites of the fruit bats in Kerala. “It has to be revived and we hope to bring in all citizens to help us map the possible area where these bats are found in large numbers. We will activate it again. The app can be used by any smartphone user who will just have to record the bat and put in simple details like location, etc. The geotagged app will in the next one year probably ready us with a rough idea of bat breeding sites in the state,” Nameer said.The study published in 2019 included researchers from top US institutions including the John Hopkins department of epidemiology, Montana State University, University of Georgia, and Cary Institute of Ecosystem Studies, Millbrook.“These machine-learning approaches provide the first step in the sequence of studies required to assess the risk of Nipah virus spillover in India. Nipah virus surveillance not only within Kerala but also elsewhere in India would benefit from a research pipeline that included surveys of known and predicted reservoirs for serological evidence of past infection with Nipah virus (or cross reacting Henipaviruses). “We suggest surveillance of these species as well as studies on the ecological dynamics of Nipah virus and epidemiology of spillover transmission to humans. This work will help prioritize a research agenda for responding to the recent outbreak of Nipah virus in Kerala, India and elsewhere,” the study said.