Since late January, Jayanthi Kallam, founder and executive director of Avian and Reptile Rehabilitation Trust in Bengaluru, has received around 17 calls from worried residents, asking for bats to be removed from their vicinity. The callers fear that the bats might be carriers of SARS-CoV-2, the virus that caused COVID-19. This, however, is a misconception.
Even Bollywood superstar Amitabh Bachchan recently tweeted something to this effect – he said on April 25 that a bat had come into his room and was driven out with a lot of difficulty. “Corona just won’t stop following me!” he added. People were quick to respond to him, including an Indian Forest Service Officer, saying he should not demonise bats and spread false information, even in jest.
Not in good taste sir. You have millions of followers. Still we don’t have exact process of human virus spillover. Demonising bat is last thing we want. Things we know for sure; They are pollinators. They help in pest control. Please revisit it.
— Parveen Kaswan, IFS (@ParveenKaswan) April 25, 2020
In an attempt to dispel the misinformation linking bats with COVID-19, 64 scientists in South Asia, including India – from institutes like Ashoka Trust for Research in Ecology and the Environment; Biodiversity Research and Conservation Society, Hyderabad; Indian Institute of Science and many others – have issued a statement, clarifying many misconceptions and busting myths.
The letter states that the exact origin of SARS-CoV-2 is not known, and it is premature to blame bats or any other animal for the pandemic. It is also very unlikely that viruses like SARS are transmitted directly from bats to humans.
The Indian Council of Medical Research and the National Institute of Virology, had, almost two weeks ago, released a study stating that they had found strains of coronaviruses in two bats – the Indian flying fox, and Rousettus, a type of fruit bat. The study had also stated that there is no evidence for bat coronaviruses being transmitted to human beings.
Even so, the study fuelled panic around bats, possibly because people did not understand that coronaviruses are a family of viruses, and SARS-CoV-2 is just one strain, Jayanthi, one of the signatories to the letter, tells TNM. Only 5% of the screened bats in the ICMR study had samples that the bat coronaviruses (BtCov) were detected in. BtCov cannot cause COVID-19.
While it is true that bats carry many zoonotic viruses, there is not enough evidence to say that direct bat to human transmission is possible. “It is also highly improbable that the faeces of bats pose an immediate health risk to humans and, none of the previous zoonotic disease outbreaks, globally, show any evidence that they were caused due to contact with bat faeces,” the letter says, adding that fungal infections, however, can result from unprotected contact with the excreta of any wild animal.
Bats are vital parts of the ecosystem. For instance, fruit bats help pollinate important cash crops like durian, and agave (the plant that helps in making tequila). Fruit bats also pollinate mangroves, which, apart from being the first line of defense against disasters like floods, are also crucial to the environment.
Many bats also eat insects that cause economic losses for crops, thus potentially saving thousands of US dollars; or insects that carry other pathogens. “The importance of bats as seed dispersers, pollinators and pest controllers, particularly in the region’s important cash crops (like tea) is beginning to be unraveled,” the letter states.
If bats are forcibly removed from such ecosystems, the effects can be quite dangerous.
“For example, lots of insects like mosquitoes also carry pathogens and can cause diseases. If insectivorous bats are removed from the equation, the insects could also lead to a host of diseases among flora, fauna and humans,” Jayanthi explains.
The signatories to the letter also point out that bats have a unique immune system, the study of which could be seen as a solution to disease outbreaks rather than the problem.
Rajesh Puttaswamaiah, a signatory and trustee of the Bat Conservation India Trust in Bengaluru, explains, “Bats carry many zoonotic viruses. However, their immune system is such that they don’t get infected by the viruses in a way that is bad for them.”
“Studying this suppression quality in the bats’ immune systems, where they can have high viral load without it turning into a harmful infection could help in development of vaccines, plasma therapies and so on,” Jayanthi adds.
However, the problem arises when people try to forcibly remove the bats by bursting crackers, clearing their roosting spots or smoking them out. Experts say that this puts the bats under stress, which could possibly lead to pressure or malfunction in their immune system also.
“When their immune systems do not produce enough antibodies for the zoonotic viruses they carry due to stress, there is a higher chance of infection. Any population undergoing stress is a likelier host for viruses and other infections. There needs to be just one spillover incident – meaning where the virus from the animal spills over to an intermediary host; or sap, water or fruit as it happened in the case of the Nipah outbreak in Kerala. Once a human being is affected by this, the infection enters into the transmission stage where a human host can pass on the infection to another,” Jayanthi says.
The letter also states that it is usually human intervention that has resulted in disease outbreaks. “Habitat fragmentation, global wildlife trade and wet markets, large-scale industrial farming of wild and domestic animals have synergistic effects in bringing animals in close contact in unsanitary or stressful conditions — ideal conditions for the transmission and evolution of novel zoonotic viruses.”
While Jayanthi says that it is natural for people to feel scared in this situation, she adds that it is the responsibility of the scientific and conservation community to dispel myths, and correct information in a simple and clear manner.
“Bats have been living around us for centuries and we have been disease free wherever bats have been left to their business. Oversimplified or unverified information from the press not only creates unnecessary fear among the public but also pushes decades of conservation efforts backwards which is far more destructive for the ecosystem,” the letter says.
Further, when people try to remove bats from their habitats, they are also exposing themselves to unsafe exposure to the bats. To remedy that, Rajesh says that practices need to change – for instance, people who collect sap should cover the containers so that no bat or rodent can get into them. Those living in areas surrounding forests should also be careful to not distress bats or other animals as much as possible to avoid infections.
“The current pandemic is an outcome of the ongoing ecological destruction, increasing intensification of livestock farming and wildlife trade. We urge people not to believe in news from unverified sources and cause harm to bats in retaliation. Likewise, we request the media to not oversimplify scientific evidence, to emphasise the role of humans in disease outbreaks and to highlight the importance of coexistence with bats in urban landscapes,” the letter says.