Why do bats carry so many viruses and they can still live well?
Bats are considered a possible source of the coronavirus outbreak in China. Facts have proved that bats may have a special immune system that can coexist with many deadly viruses.
If there are any signs of previous coronavirus outbreaks, the Wuhan strain that is now circulating may eventually be traced to bats. Dr. Peter Daszak, Chairman of the Eco-Health Alliance, has worked in China for 15 years and has studied various diseases from animals to humans. He said: “We don’t know the cause of the disease yet, but there is sufficient evidence that this It's a bat. He said: "It may be a horseshoe bat from China, which is a common species that weighs ounces. "If he is right, this strain will be combined with many other viruses carried by bats. The SARS and MERS epidemics are caused by bat coronaviruses, as are the highly destructive viral epidemics in pigs. A bat can be infected with many different viruses without getting sick. They are natural reservoirs of Marburg virus, Nipah virus and Hendra virus, which have caused human diseases and have broken out in Africa, Malaysia, Bangladesh and Australia. They are thought to be natural reservoirs of the Ebola virus. They also carry the rabies virus, but in this case, bats will be affected by the disease.
Their tolerance to viruses exceeds that of other mammals and is one of its many unique qualities. They are the only flying mammals, they devour disease-carrying insects in large numbers, and are essential in the pollination of many fruits such as bananas, avocados and mangoes. They are also a very diverse group, accounting for about a quarter of all mammalian species. However, their ability to coexist with viruses will spread to other animals, especially humans. When we eat them, buy and sell them in the livestock market, and invade their territory, it may have devastating consequences. Understanding how they carry and survive so many viruses has always been a deep question in the scientific community, and the latest research suggests that the answer may be how bats’ evolutionary adaptation to flight changes their immune systems.
In a 2018 paper in Cell Host and Microbe, scientists from China and Singapore reported on their research on how bats handle DNA induction. The energy demand for flight is so great that the cells in the body break down and release some DNA, which then floats where they shouldn’t exist. Mammals (including bats) have a way of recognizing and responding to such DNA bits, which may indicate the invasion of certain pathogenic organisms. But they found that the evolution of bats weakened this system, which usually causes inflammation when fighting viruses.
Bats have lost some genes related to this reaction, which makes sense, because inflammation itself can cause great damage to the body. Their response diminished, but it remained. Therefore, the researchers wrote that this weakened response may allow them to maintain a balanced state of "effective response" to the virus, rather than maintaining an "overreaction" to the virus. Of course, how to manage and contain the current outbreak of the virus officially known as nCoV-2019 is crucial. However, tracing its origin and taking action to fight further outbreaks may depend in part on the knowledge and monitoring of bats. Dr. Dasak said: "The epidemic can be controlled." "However, if we do not know the origin for a long time, then this virus may continue to spread." Chinese scientists have been studying bats carefully, and they know very well that it is like the present. The big outbreak is likely to happen.
Last spring, in a group of articles about bat coronaviruses or coronaviruses, a group of Chinese researchers wrote: “It is generally believed that bat-type coronaviruses will reappear and trigger the next disease outbreak.” It may not be a hot spot. This is not clairvoyance, but a traditional view. Of course, rodents, primates, and birds also carry diseases, and these diseases may jump around. In this regard, bats are not alone. However, there are some reasons why they are related to multiple disease outbreaks, and possibly more diseases. They are numerous and widely distributed. Bats account for a quarter of the mammalian species, and rodents account for 50%, and then we are the rest. Bats live on every continent except Antarctica, adjacent to humans and farms. The ability to fly makes it spread widely, which helps spread the virus, and their feces can spread diseases. People in many parts of the world eat bats and then sell bats in live animal markets. This is the origin of SARS, and it may also be the recent outbreak of the coronavirus in Wuhan. They also often live in huge colonies in caves, where crowded conditions are perfect for spreading viruses.
In a 2017 report in Nature, Dr. Daszak and Kevin J. of the Ecological Health Alliance influenced their owners. They confirmed the scientists' thinking: "The proportion of zoonotic diseases in bats is much higher than that of all other mammals." Zoonotic diseases are diseases that spread from animals to humans.
And they can not only survive the viruses they carry. For small mammals, bats have a very long life span. Big brown bats are very common in the United States and can live in the wild for nearly 20 years. The life expectancy of others is close to 40 years. A little bat in Siberia lived at least 41 years old. Animals like house mice live for about two years on average.
Although bats must be studied, it is necessary to understand the physiological mechanisms of bats and monitor the viruses they carry for the sake of public health, but this does not mean that bats should be blamed for the outbreak of the virus. As others have pointed out, humans have violated the lives of bats and vice versa. Dr. Dasak emphasized that stopping the sale of wild animals and plants on the market is essential to contain future outbreaks. However, since such outbreaks are inevitable, Dr. Dasak said that monitoring and studying wildlife such as bats is equally important. He compared the situation with terrorism. Both terrorist attacks and disease outbreaks seem inevitable. He said that in order to catch up with them, intelligence is essential.