Presence of bat coronavirus BtCoV in two bat species: ICMR study

By Priyanka Sharma
New Delhi [India], April 15 (ANI): A first-time study in India by the country's top medical research body Indian Council of Medical Research (ICMR) has detected the presence of bat coronavirus (BtCoV) in two bat species from Kerala, Himachal Pradesh, Puducherry, and Tamil Nadu.
However, the study clearly mentions that there is no evidence or research to claim that these bat coronaviruses can cause disease in humans.
"Bats are considered to be the natural reservoir for many viruses, of which some are potential human pathogens. In India, an association of Pteropus medius bats with the Nipah virus was reported in the past. It is suspected that the recently emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) also has its association with bats," stated the study which is published in the Indian Journal of Medical Research (IJMR).
According to the study, bats were trapped using mist nets and were chemically restrained using isoflurane anaesthesia. Throat swabs (TS) and rectal swabs (RS) were collected in virus transport medium (VTM) and were transported to ICMR-NIV, Pune, on dry ice.
The specimens were collected from Pteropus species bats from Kerala, Karnataka, Chandigarh, Gujarat, Himachal Pradesh, Odisha, Puducherry, Punjab, Tamil Nadu, and Telangana and Rousettus species bats from Kerala, Karnataka, Chandigarh, Gujarat, Odisha, Punjab and Telangana States during 2018-2019.
Dr Pragya D Yadav, Scientist at NIV-Pune, author of the study, said: "Twenty-five bats of Rousettus and Pteropus species from Kerala, Himachal Pradesh, Puducherry and Tamil Nadu were found positive for BtCoV. But these BtCoV have no link with SARS-CoV2 responsible for the COVID-19 pandemic around the world. In the last two years, Pteropus bat species were found positive for the Nipah virus in Kerala."
"To assess the presence of CoVs in bats, we performed identification and characterisation of bat CoV (BtCoV) in Pteropus and Rousettus species from representative states in India, collected during 2018 and 2019," she said.
In India, regions of the Western Ghats, particularly in Kerala, are habitats for diverse bat populations. The reports of pathogenic human viruses from bat specimens demand enhanced methods to monitor human exposure to various bat species. Investigations in unexplored regions and states should be focused on gaining further insights into CoV diversity within Indian bat populations.
"In the present scenario of changing demography and ecological manipulations, it is challenging to have checks on the encounters of bats with other animals and humans. Therefore, active and continuous surveillance remains crucial for outbreak alerts for bat-associated viral agents with epidemic potential, which would be helpful in timely interventions," pointed the study.
Although CoVs in the subfamily Coronavirinae do not usually produce clinical symptoms in their natural hosts (bats), the accidental transmission of these viruses to humans and other animals may result in respiratory, enteric, hepatic or neurologic diseases of variable severity, it noted.
The study mentions that it is still not understood as to why only certain CoVs can infect people. "There is a need for proactive surveillance of zoonotic infections in bats. The detection and identification of such viruses from bats also recommend cross-sectional antibody surveys (human and domestic animals) in localities where the viruses have been detected."
"Similarly, if the epidemiological situation demands, evidence-based surveillance should also be conducted. There is a need for developing strong mechanisms for working jointly with various stakeholders such as wildlife, poultry, animal husbandry and human health departments," said ICMR scientists.
"In conclusion, our study showed the detection of pathogenic CoVs in two species of Indian bats. Continuous active surveillance is required to identify the emerging novel viruses with epidemic potential," said Dr Yadav. (ANI)