Why Do Bats Carry So Many Viruses (Including Coronavirus)?


Gabrielle Ott, Editor

Huanan Seafood Market in Wuhan China has been recently getting a lot of publicity. It’s where scientists and experts say the new COVID-19 virus was first spread to humans. This market sells, as the name suggests, seafood, but also a selection of wild animals such as snakes, pangolins, and bats. Bats. Whenever the topic of diseases comes up, this mammal often seems to have some sort of role in it. Across the different species, they host more than sixty different zoonotic viruses. Zoonotic viruses are viruses that jump from animals to humans, such as the new coronavirus, Ebola, and SARS. Bats aren’t the only kind of animal that carry these viruses. In fact, some newer research suggests that not only bats but pangolins, a very endangered and highly trafficked armadillo-like mammal, could have played a role in the transmission of the coronavirus to humans. And pigs can spread swine flu, civet cats spread the SARS virus, and even your own dog could carry rabies if it was not vaccinated. But what is it about bats that makes them such virus carrying machines? 

First, a question that was first asked by researchers was how come these diseases, some of which have a very high mortality rate in humans, can live in bats without killing them? The answer all has to do with the fact that bats are the only flying mammal on Earth. For any other mammal, humans for instance, to fly, we would need to produce a huge amount of energy that we don’t really have. But bats can produce this energy, and they have been since they have become creatures. Evolution plays a key role in how bats manage this energy because when they fly, it takes so much energy that their bodies create a toxic chemical that is kind of like excess energy. In the early stages of bats, these toxic molecules would make their wings weak and they would eventually die. Over time though, the bats developed an immunity to the molecules which allows them to not be affected anymore. However, when bats developed this immunity it also gave them a strong immune system and body in general that allows them to not be harmed by viruses that can be deadly to humans. This means that the bat can host a virus and not be affected, therefore living in harmony with it. 

Now that we begin to understand the immunity bats have to certain viruses, a key piece of information is how they spread. One way that viruses can very quickly spread from bat to bats is in caves where they sleep and where young stay. Since bats are very social creatures, they come together in masses to make their homes in caves, abandoned barns, and other places that make a good home. In these colonies, bats are closely packed together, allowing viruses to jump from bat to bat in a matter of hours. Of course, this doesn’t kill off the bat population, but it does infect more bats which means more chances for the virus to encounter humans in places like wet markets. Bats can also infect other animals in markets where cages are stacked directly on top of each other with animals inside that don’t meet in the wild. This can lead to outbreaks like the one we are facing now.  

But bats aren’t the ones to blame, and they aren’t the criminal of outbreaks. Lots of human activity such as construction causes bats to leave their normal habitats and relocate to places much closer to humans. And of course, when humans capture and breed bats to sell for food, this isn’t a natural thing for the bat population and leads to lots of human contact with bats. Researches can also study bats to learn from them and maybe create vaccines or cures for viruses. 

Overall, bats can carry viruses that are sometimes fatal to humans because they are able to fly. Their bodies have become strong enough to overcome the deadly complications that come with flying and because of that they have built up and immunity to lots of viruses. We can avoid the threat of future pandemics by not venturing further into bats habitats and disrupting their lives, as this can lead to them moving closer to larger human populations. There will probably be some sort of virus or bacteria outbreak in the near or far future, and as there are, we have to remember to do all we can to keep ourselves and others healthy. 

Included below are the videos that I watched to gather infromation for this article.