Colorado State researchers link bats to Ebola, other diseases

Stephanie Mason

Bats have become a popular study topic at Colorado State University because of their disease-carrying capacity.

“Over the past 20 years, it has been discovered that bats are infected with a lot of viruses that kill people,” said Charles Calisher, microbiology, immunology and pathology emeritus professor. “Once that was found, the money came for other people to do more studies.”

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Researchers at CSU take a close look at the transfer of viruses between bats and other animal species.

“The idea behind emerging viruses is to discover them before they cause epidemics,” Calisher said. “Viruses pop up in places you just wouldn’t imagine.”

The transmission of viruses from animals to humans is known as zoonosis. SARS, MERS, Marburg, rabies, Hendra, Neph and possibly Ebola are diseases that are spread by bats. These diseases are what Schountz refers to as “the big seven.”

“Bats are at the basis of this,” Calisher said. “They don’t get sick, as far as we know. They don’t die. They just shed out all these viruses.”

There are around 1,200 species of bats. Twenty percent of known animal species in the world are bats, and they are the second-largest group of animals behind rodents.

“Any time somebody goes out and collects a bunch of bats, they (discover) a virus,” Calisher said. “We are finding viruses very quickly.”

Cliff McKee, a graduate ecology student, is researching the transfer of Bartonella disease between bats and humans.

”There is an interest in knowing how much contact is there that leads to humans being infected to some degree,” McKee said. “We have no idea.”

Discoveries about bats are essential to understanding recent disease outbreaks.

“You’ve heard of Ebola … It’s probably a bat disease,” said Tony Schountz, associate professor in the CSU Department of Microbiology, Immunology & Pathology.

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According to Schountz, Ebola is thought to be spread by bats because of the close relation of Ebola to a similar infection carried by bats called Marburg virus. Though there is strong evidence, there is still uncertainty.

“I think what is missing is this last smoking gun of finding a virus in a bat,” McKee said.

Not much is known about bats’ ability to carry diseases without being infected.

“What’s special about the ecology of (bats)?” McKee said. “There may be a greater capacity to deal with the capacity with what is called the innate immune system.”

According to McKee, bats play an important ecological role. They get rid of pest species and help with pollination.

Last June, Schountz organized a conference held in Fort Collins for those interested in bat research.

“It was an effort to get the world’s leaders in bat infectious research together,” Schountz said. “It went really well … The idea was that we could sort of get everyone together and not only share our research activities, but our obstacles and hurdles we were having.”

According to Calisher, bat biologists typically reject the new disease findings in bat populations.

“These bat people are trying to protect them,” Calisher said. “They don’t want you to collect them because … poor little darlings are bad mouthed by everybody.”

Bats are a new popular topic among researchers.

“Why bats all the sudden? Because no one ever studied them before,” Calisher said. “Bats tend to be at a lot of these medical mysteries, so that’s why people are all interested in bats.”

Collegian Science and Technology Beat Reporter Stephanie Mason can be reached at news@collegian.com or on Twitter at @stephersmason.