Some researchers have argued that snakes might have been the original source of the Wuhan coronavirus. But there are infectious disease experts who point out to bats as the ultimate culprit.
“When you look at the genetic sequence of the virus, and you match it up with every known coronavirus, the closest relatives are from bats,” said Dr Peter Daszak, president of EcoHealth Alliance, an environmental health non-profit.
This is not the first time bats are being portrayed as a biological supervillain. Deadly virus outbreaks such as Marburg, Nipah and Hendra is suspected to have reached humans from bats. Bats are thought to be the natural host of the Ebola virus, rabies, SARS and MERS. Genetic evidence suggests that the new virus shared similarities with both SARS and MERS.
While SARS and MERS had intermediaries involved in the form of civet cats and camels, Nipah infection was traced back to juice made from the sap of date palm trees contaminated by bat urine or saliva. For many virologists, new coronavirus being linked to bats comes without any surprise. According to the virologist, Dr Stathis Giotis “Bats are recognized as important reservoirs for emerging and re-emerging viruses with zoonotic potential.”
It is amazing how a single group of animal can act as a reservoir for such large variety of viral infections. Bats are a diverse group with more than 1,300 species, living on every continent except Antarctica. Add to that they live longer and live as densely populated crowds.
Their sheer number makes it possible that they come in contact with every kind of viruses there is. Since they live in large numbers it becomes so easy to circulate all the viruses so easily within themselves. An equally fascinating fact is that except for rabies none of the other viruses seems to have an effect on these creatures.
We don’t know the exact reason. But some scientists attribute this to its ability to fly. Being a mammal, that’s able to fly the body metabolism in bats are much higher than other mammals. Higher metabolism and the associated temperature increase is comparable to the effect of fever we have, boosting their immunity and making them inherently immune to these viruses.
While bats are one of the notorious carriers of zoonotic viruses, we cannot leave the other animals guilt-free. For example, the deadly plague is carried over to us by rats and HIV was originally something found only in certain chimpanzees.
So, are bats the ultimate supervillains? We can’t say for sure, at least by the opinion of some scientists. If other animals may are looked into, more robustly just like how we examined during the SARS outbreak we might find a similar diversity of viruses. As for coronavirus, more and more studies are coming in suggesting bats as the culprits. But it is still too early to be sure.
Rapid urban expansion has put more people in contact with bats. This kind of increased exposure to bats comes with the risk of endemic emergence of new viruses.