Since 2005, tens of millions of bats around the world have developed "white noses" and millions of bats have died from this white-nosed syndrome, a disease caused by the devastating pseudogymnoascus destructans. Although the disease has been found in many parts of the world, why is it that bats die in large numbers only in North America? Scientists from Virginia Tech recently found the answer.
Recently, in a new PNAS study led by Joseph Hoyt, an assistant professor in the Department of Biological Sciences at Virginia Tech's School of Sciences, researchers found that pathogen levels in the environment play an important role in whether bat populations are stable or experience severe declines in white nose syndrome. Hoyt and his international team published their findings March 16 in the Proceedings of the National Academy of Sciences.
"This study suggests that more polluted environments, or potential 'hot spots', will lead to higher disease impacts." "By understanding the relationship between how many pathogens there are in the environment and the scale of the disease's transmission, we can know exactly how much sanitation treatment is needed to reduce the likelihood of transmission," Hoyt said. ”
When infectious diseases first appear, it is crucial to understand how the disease spreads. Using a pseudospoon-like pathogen that can exist outside the host, the researchers looked for environmental pathogen reservoirs or habitats where the pathogen persisted or grew without a host.
The devastating pseudospoon is a cold-loving fungus that lives on the walls of caves, mines, and other underground environments. Every year, when the cold winter is approaching, bats hibernate in these infected places and do not return to nature until spring. It was during this time that bats developed white nose syndrome.
When Hoyt and his team set out to find the disease's historical origins, they were the first to discover that the pathogen had been present in Asia for thousands of years. In a more shocking finding, they found that European and Asian bat populations were almost unaffected by white-nosed syndrome compared to North American bats.
This unprecedented study shows that reservoirs of environmental pathogens in Europe and Asia gradually decay over the summer months, which reduces the number of pathogens in the environment and allows bats to come into contact with them in the following winters. In contrast, the decline of no pathogens in the North American region during the summer has led to widespread infection and death.
The truth is that bats are much less infected at the beginning of the hibernation season throughout Europe and Asia. As a result, they are still infected, but the infection process is delayed compared to North American bats. As a result, they spread much less in the environment than bats in North America. With low transmission of the pathogen and support for a period of time, bats will be able to break free from the infected state in enough time to escape death.
"Because pathogens decline in the environment during the summer in Europe and Asia, most bats are not infected until midwinter to late winter, which is too late for infected people to cause death." "If you delay transmission, then bats are able to emerge in the spring and clear the infection before they die," Hoyt said. ”
Hoyt and his team are now trying to use the discovery of Eurasian bat populations to help North American bats. More specifically, they are trying to reduce the number of pathogens infected in bats in the summer Environment in North America. "We are trying to replicate the decline of pathogens that are happening in Europe and Asia and delay transmission." "If we could get bats infected later in the winter, they might survive until spring," Hoyt said. ”
A small difference in the environment can lead to a huge change in the organisms that live in it, such as the adaptability of Eurasian bats and North American bats to pathogens above. This also reminds us that we should not change the environment at will and maintain the stability of the environment in order to achieve sustainable development and maintain ecological stability.