Hyderabad: Among the many absorbing facts that have come-out from the outbreak of COVID-19 (coronavirus disease 2019) in Wuhan, China, the one development that should hold the attention of public health officials and epidemiologists in India is the ‘jump’ of the coronavirus from animal species to human beings.
To prevent similar outbreaks from taking place in India, understating the process of transmission of such diseases and being able to zero-in on the zoonotic link behind COVID-19, especially in the Indian context is of vital importance, senior zoologists and epidemiologists here point out.
According to the latest report from the World Health Organisation (WHO), there is enough evidence demonstrating a direct link between 2019-nCoV and other similar coronaviruses (CoV) circulating among the bats, and more specifically the Rhinolophus bat sub-species.
Rhinolophus bat sub-species in Hyderabad and Telangana
The Rhinolophus bat sub-species are abundant and widely present in Southern China and across Asia including India, Middle East, Africa and Europe. According to bat zoologists, there are 16 to 17 bat species that are very well spread in the Himalayan and Peninsular region of India.
In fact, in Telangana there are two-specific Rhinolophus bat sub-species including Rhinolophus lepidus and Rhinolophus rouxii.
“Over the years, these sub-species have been sighted frequently in Hyderabad at several locations. They are more common in the cave systems along the river Godavari. However, one must also remember that there is very little human and bat interaction at these particular habitats,” says zoology professor and an expert in bats, Dr. Chelmala Srinivasulu.
What WHO says?
According to the WHO technical report, recent studies have indicated that more than 500 different types of coronaviruses have been identified in bats in China. There have been studies that have indicated that human exposure to bat-coronavirus is quite common in China.
However, that kind of specific studies on the relationship between bats and human population is not available in India, although there are anywhere between 16 and 17 different Rhinolophus bat sub-species.
The WHO reports has made it clear that they are yet to figure out the route of transmission to humans at the start of COVID-19 in China. ‘Bats are rare in markets in China but hunted and sold directly to restaurants for food. The current most likely hypothesis is that an intermediary host animal has played a role in the transmission of 2019mCoV,’ the WHO said.
“Bat species are natural reservoirs for various groups of parasites and viruses and that’s why they are considered as a unique group of animals. Over the years, they have developed resistivity towards such viruses and parasites. As a species they have managed to survive despite the frequent human intervention in the form of destruction of their natural habitat,” Dr. Srinivasulu explains.
According to WHO, at present, experts from China and outside are trying to identify the animal that has acted as an intermediary and has spread the virus from bats to human beings.
Challenges in Indian context
Every time a virus or a parasite jumps or transfers from one organism to another, it tends to change or mutate. Hence, it is very difficult or challenging to fully understand the entire lifecycle of how the virus is transferring from one species to another and its impact on the organism, Dr. Srinivasulu says.
Like in any other zoonotic case, this specific case of 2019-nCoV, the virus from the wild animal i.e. bat has through a vector transited to humans. “Quite often, under stress or certain conditions like reduction of immunity levels in bats, the viruses look to ways to move out of the host to a healthy host. This is when transfer happens and finding the exact route of transmission is the challenge,” Dr. Srinivasulu said.