Chiroptophobia: COVID precipitates widespread fear of Bats in India
Story in brief
Reports indicating links between the SARS CoV-2 virus and bats has led to mass hysteria and fear of bats in India.
While bats, like many other wild animals, function as reservoirs for several zoonoses, it is highly unlikely for SARS-like viruses to jump directly from bats to humans.
It is important to recognize the pivotal role that human activities such as wild life trade and industrial livestock-farming play in the causation of zoonotic spillovers.
Bats perform vital ecosystem services including pollination and pest control. These functions are indispensable to myriad communities around the world.
It is vital that society is made aware of the need for bats and makes strides towards healthy coexistence primarily by leveraging epidemiological facts in decision making.
According to the Bangalore Mirror, The Bruhat Bengaluru Mahanagara Palike (BBMP) has reported that requests to remove bats from neighborhoods in Bengaluru have been pouring in ever since early, unconfirmed reports linked the novel Coronavirus (SARS CoV-2) to bats. Fueled by fear and rumor, people have been reaching out to have fruit trees uprooted and destroyed to ward off bats as well.
This fear of and hatred towards bats has only worsened since a study published by the Indian Council of Medical Research (ICMR) revealed that a different kind of Coronavirus -- Bat Coronavirus (BtCoV) -- had been isolated in two bat species from Kerala, Himachal Pradesh, Puducherry and Tamil Nadu.
"There is no evidence or research to claim that these bat Coronaviruses can cause disease in humans", said Dr. Pragya D Yadav, Scientist at the National Institute of Virology (NIV), Pune and also the first author of the study to Bangalore Mirror.
Given the highly debatable link between bats and the recent COVID-19 outbreak, is this fear rational, i.e., are bats dangerous, and should they be actively controlled? More importantly, can their mass culling have adverse effects on the environment and on our lives?
Bats and disease
Bats and bat-related zoonoses comprise some of the most studied topics in recent scientific literature. These studies have revealed over nine species of viruses that contain genetic material that can be traced to bats. In recent history, diseases such as Rabies, SARS, MERS, Ebola virus disease and Influenza A have all been partly linked to wild, geographically isolated populations of bats.
In each of these cases, bats have been identified as potential reservoirs. In truth, like any other animal, bats are also reservoirs of many zoonotic viruses. However, being reservoirs does not mean that they spread diseases to humans. In reality, there is very little scientific evidence to prove bats have directly transmitted viruses to humans or caused outbreaks. The only known exceptions were the Nipah (NiV) outbreaks in Bangladesh and India which were caused through indirect contact between bats and humans.
The Nipah virus (NiV) has been reported to have caused outbreaks in Bangladesh and India since 2001. In 2018, a localized outbreak of NiV in Kerala led to 17 deaths. Post outbreak surveillance revealed limited human-to-human transmission and the WHO attributed most of the cases to indirect contact with wild bat saliva and feces during the harvest and consumption of date palm sap. In addition, the WHO recommended conducting further research on the ecology of bats and avoiding direct contact with wild populations. Further, no direct actions against bats were recommended by the WHO.
The damage, however, had already been done. As soon as the Nipah reports surfaced, several individuals began reaching out to the authorities and demanding the removal of bats in their neighborhood. An email complaint demanded action alleging that there was a huge risk to him and his family due to a population of bats that were inhabiting a nearby tree. Several others had themselves uprooted several fruit trees and used myriad methods to rid trees of bats.
But, regardless of any other consideration, wouldn't the removal of the reservoir -- bats -- through their culling lead to ultimate the wild circulation of these viruses? What, if any, are the negative implications of controlling wild bat populations?
What do we stand to lose if we cull wild bats?
In response to the rampant fear of bats fueled by the COVID-19 outbreak, a group of South-Asian scientists and conservationists published a press-release urging the international community to recognize the importance of bats. Referring to the NiV outbreak, they argued that once the cause of the outbreak was identified, it became easy to control and prevent subsequent NiV outbreaks through basic precautionary and mitigation measures. Citing literature, they alleged that the real drivers of zoonotic diseases including NiV were predominantly man-made actions such as habitat fragmentation and global wildlife trade. In addition, they urged policy makers and community leaders to recognize the benefits of bats.
1. Bats and pollination:
Fruit bats are the primary pollinators of important crops like Durian, Mahua, Chiuri and Agave. Further, these bats also pollinate Mangrove flowers. Mangroves are invaluable natural barriers to coastal erosion and tidal waves.
2. Bats as pest control:
Insectivorous bats are highly effective at controlling pest-insect populations especially in rice plantations. According to a study by TC Wanger et al, in 2014, bats are estimated to save $800 million for coca farmers in Indonesia annually. Interestingly, bats are also voracious feasters on mosquitoes which are known vectors of Malaria, Dengue, Chikungunya, Filariasis and Yellow Fever.
3. Bats as early indicators of outbreaks:
It is posited that the unique immune systems of bats hold valuable clues on handling viruses. Further, their genetic codes and zoonotic viruses harbored in their bodies could reveal impending outbreaks among humans. In this regard, bats could even be seen as potential solutions to disease outbreaks.
How do we prevent zoonoses then?
At the very essence of such outbreaks as COVID-19, is a set of human activities that brings humans closer and closer to invading habitats that should ideally belong to animals. Human encroachment not only displaces animals but also places animals in a stressed state where they are likely to exhibit unsafe behavior. By drafting decisions based on oversimplified and unverified information from the press and villainizing animals during each of these outbreaks, we run the risk of losing vital components of our ecosystem which may in fact be benefiting us far more than harming us.
More about controlling zoonotic spillovers:
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It is perhaps more prudent to reconsider, enact and reinforce laws to conserve animals and establish mechanisms to direct human activities away from wildlife to bring us closer to the ever-elusive state of peaceful co-existence.