Why Are Bats Infected With Many Dangerous Viruses Like Corona But Not Dead?

Bats have long been considered the leading cause of disease, because they themselves are large reservoirs of viruses.

Bats are infected with many dangerous viruses such as rabies, Sars, Mers and COVID-19, all of which are caused by coronaviruses believed to have emerged from bats. While these viruses can cause death in other mammals, but not with bats. In fact, they can live up to 30 years normally. So what is protecting them from these dangerous diseases?

Since the initial SARS-Co V outbreak in 2002, these coronaviruses closely related to SARS-Co V have been detected in bats from countries around the world. Scientists in China studying Chinese horseshoe bats in 2013, identified several SARS like Co Vs that use the same ACE2 receptor to bind to cells as present-day SARS-Co V-2 in.

In 2017, an infection spread to a herd of pigs on a livestock farm in Guangdong province, China. The herd suffered severe diarrhea, and at least 24,000 pigs died. Fatal acute diarrhea syndrome in pigs is caused by a new virus originating from coronavirus found in bats, according to the results of an investigation by a scientific team first published in the British scientific journal.

 A few years later, humanity was officially attacked by another coronavirus, called SARS-Co V-2, and it is unfortunately also closely related to bats. According to a scientific report, 96% of the genome of the new coronavirus, or its total genetic information, matches the coronavirus genome in the large horseshoe bat, which lives in Yunnan province, China.

So there is considerable diversity of coronaviruses circulating in bats, which could increase the probability that one of these viruses has the potential to become zoonotic.

The Ebola virus, which has a mortality rate of up to 90% in humans, and the Nipah virus, which has a mortality rate of 40% to 75%, both originated in bats. As of 2016, 5,629 viruses, including non-pathogenic ones, have been detected in bats.

Why are bats responsible for so many diseases? It's because of their lifestyle and the way their bodies work.

To answer this question, we first need to understand the relationship between viruses and their hosts. Each virus has evolved to infect specific species. This is why humans are unlikely to get infected with plant viruses and why bees don't get the flu. However, viruses sometimes evolve and infect new, related species. And because the new species' immune system does not yet have specific antibodies to fight the virus, it can cause the host to die.

This is really bad news for the virus. An ideal host that the virus targets is having a stable resource for the virus to grow and continue to infect, only a living host can meet these two criteria. Therefore, successful viruses often do not evolve to kill their hosts.

The deadly effects of these viruses are often not caused directly by the pathogen, but by the host's uncontrolled immune response. Infections such as Ebola or certain types of influenza overwhelm the host's immune system. The body sends white blood cells, antibodies, and inflammatory molecules to destroy foreign invaders. But if the inflammation is too high, the immune system is attacked which can lead to severe tissue damage, infection and death.

 

Why are bats infected with a dangerous virus but not dead?

 

Apparently, bats can maintain a balance between controlling viral infections and an over-inflammatory response that can kill other hosts. Perhaps the answer lies in their unique feature among mammals: flight.

 

The physiological requirements of flight influenced the bat's immune system. Flight causes bats to boost their metabolic function and raise their core body temperature to about 38°C. This means that bats are often in a state that, to humans, can be considered a fever. Researchers in the UK have suggested that this may be the mechanism that helps bats survive viral infections.

Partial viral infection can harm the host by triggering an uncontrolled inflammatory response known as a “cytokine storm,” which can be a fatal complication in a number of respiratory diseases, including including COVID-19. If bats' adaptations to flight also allow them to better tolerate high body temperatures, that means they may be able to tolerate at least some of the potential harmful effects of the inflammatory response better than mammals. is different.

In addition to the traits that allow bats to tolerate high body temperatures, bats may also have other adaptive ways that mark their immune systems as unusual or unique among mammals.

Unlike other mammals, bats have been in an evolutionary arms race with these viruses for millennia, and they have adapted to minimize self-harm mechanisms. Their immune systems have a very low inflammatory response, which is a great adaptation.

Evolution has lost several genes involved in the deployment of inflammatory molecules in bats. The result is a controlled, low-level inflammatory response that allows bats to coexist with the virus. Low response does not mean that bats lose their immune system, this is an effective immune response mechanism, not an overreaction leading to self-destruction. Even more impressively, bats can harbor these viruses for decades without any negative health consequences.

In addition, bats have also developed an efficient system of repairing damaged DNA, which also contributes to their longevity. Some species of bats have a lifespan of up to 40 years. Of course, bats are not completely invincible to disease. Bat populations have been ravaged by a fungal infection called white nose syndrome, which can disrupt hibernation and damage wing tissue.

Benefits Of Bats To The Environment.

 

Although it can be said that bats are a host of many viruses that can be harmful to humans, the benefits they bring are also very significant. Bats play important roles in ecosystems such as pollination and seed dispersal, as well as consuming pests and insects.

Therefore, to protect these animals from harm and protect ourselves from dangerous infections, we need to stop encroaching on bat habitats and ecosystems.

It is hoped that conserving and continuing to study these bat populations will allow scientists to better understand the animal's unique virus-fighting immune system. And maybe in the future, humanity will find a new method of virus immunity.