Humans are to Blame for Coronavirus, Not Bats Says Scientists

Bats are being pointed out as the source of coronavirus. However, scientists claim the humans are to blame for the spread of the disease.

The rapid destruction of habitats, the increasing population, and the fast mobility of people and animals have caused the zoonotic spillover. These, according to experts, as reported on CNN, have caused diseases to spread. Stopping these human behaviors is an easier fix than developing vaccine every virus outbreak, wildlife experts say.

The Story of Bats

How the coronavirus emerged remains a question for scientists. Unless they can isolate a live virus in a suspected species, proving the novel coronavirus source is a difficult task. However, viruses extremely similar to SARS-CoV-2, the virus that causes COVID-19, have been found in Chinese horseshoe bats, making the bats a likely suspect as the virus' source.

According to Andrew Cunningham, a Professor of Wildlife Epidemiology at the Zoological Society of London, bats are the only mammals that can fly. This ability allows them to scatter over a large area, carrying with them pathogens or diseases. Bats' immune system has become very specialized owing to their ability to fly. Flying increases the bat's body temperature that mimics as fever. This increase in temperature happens twice a day: when flying out to feed and when returning to roost. The pathogens that have evolved in bats can adapt to these peaks of body temperature.

Problems arise when viruses are transmitted from one species to another through zoonotic spillover. Fever for humans, for example, is a mechanism that raises body temperature to kill a virus. Since viruses from a bat can withstand an increase in body temperature, it is not affected by fever.

When a bat is stressed, Cunningham added, from being hunted or having its habitat damaged by deforestation, its immune system is challenged and finds it difficult to manage pathogens. He likened it to having a cold sore virus when stressed, thus leading to a cold sore.

Zoonotic spillovers

The problem, according to Cunningham occurs when diseases transfer to another species through "zoonotic spillover" or zoonotic transfer. Human activities are causing these, Cunningham said.

Animals are being transported for medicine, pets, and food; this transport is happening at an unprecedented scale. Habitats are being destroyed to make way for more human-dominated landscapes, and such destruction causes stress, according to Kate Jones, Chair of Ecology and Biodiversity at University College London said.

For Cunningham and Jones, spillovers from wild animals have occurred historically, but the person infected would have died or recovered before coming in contact with a huge population in a town or city. Nowadays, however, motorized transport and planes in a forest in Central Africa can bring people to London the next day. Hence, spillover is magnified by the fact that there are so many people to transmit the viruses to.

Bats are Not to Blame.

According to Cunningham, it is the way humans interact with bats that have led to a pandemic spread of the pathogen. The immune system of bats, though poorly understood, might provide us solutions. Understanding how bats cope with pathogens can offer us clues, in cases of spillover to people, he added. To stop spillover, the critical points for it need to be identified and stopped, Cunningham suggested. Jones said destroying habitats should also be stopped and such places should be restored.

"It's not OK to transform a forest into agriculture without understanding the impact that has on climate, carbon storage, disease emergence, and flood risk," said Jones.