Study authored by U of Sask. researcher says stressed bats could spread diseases to humans

A study authored by a University of Saskatchewan veterinary microbiologist found increased stress levels in bats could lead to the spread of potentially dangerous and deadly viruses.

Habitat loss, lack of nutrition and infection can cause stress for bats and lead to virus 'shedding'

Vickram Misra and a team of researchers studied bats found in a Manitoba cave to learn how stresses like habitat loss can lead to the spread of viruses the animals carry. (Submitted by Vickram Misra)

Humans aren't alone in feeling stress. And when bats are stressed, the may expose other animals — including humans — to dangerous, and potentially deadly, viruses.

That's one of the findings of a new study conducted by an international research team and authored by a Saskatoon-based veterinary microbiologist.

The study, published this month in the journal Scientific Reports, found stress created by habitat destruction, lack of nutrition and infection leads to an increase in the production and shedding of viruses which are potentially fatal to humans.

"Bats have a really benign relationship with their viruses until you stress them through secondary infections or other stresses," said Vikram Misra, a veterinary microbiologist at the University of Saskatchewan.

"That's when they start producing and shedding more viruses."

White-nose syndrome is one of those secondary infections. The disease was first discovered in 2006 and has since spread across North America, killing millions of bats in its wake.

The disease suppresses the immune response in bats that normally helps them keep viruses in check, and increases virus replication by as much as 60 times.

Misra said white-nose syndrome affects bats even when they are hibernating.

White-nose syndrome has yet to be found in Saskatchewan's little brown bat population, although Misra said it was discovered in Manitoba last spring, which is where the latest research was conducted.

He told CBC Radio's Saskatoon Morning he expects the disease will be found here soon.

'We've got something to learn from them'

The microbiologist said researchers have seen an increase in the last 20 to 30 years in cases of diseases carried by bats transferring to other animals, including humans.

"We think it's because stresses in bats have gone up. They're more likely to shed these viruses," Misra said.

Misra said one example is Middle Eastern respiratory syndrome, which is believed to have started in bats then transitioned to camels before making a jump to humans. Ebola is another example of a virus which likely started in bats before jumping to humans.

He said moving forward, in order to prevent more diseases jumping from bats to people, he wants to study why bats sometimes don't get sick from the viruses they carry.

"We've got something to learn from them. If they don't get sick, why don't they get sick?" Misra asked. "If we can find that out, perhaps we can do something about why we get sick when we get viral infections."

With files from CBC Radio's Saskatoon Morning