Did squirrels pass a killer virus to people?

Variegated squirrel--Courtesy of Don Faulkner CC BY-SA 2.0

Three men in Germany who bred exotic squirrels as pets have died from a brain disease called progressive encephalitis, or meningoencephalitis. Now animal health experts are concerned the men caught the virus from the critters they were breeding, which were known as variegated squirrels.

An article in the New England Journal of Medicine describes a previously unknown variety of a pathogen called bornavirus that was found in the brains of both the animals and their breeders. Bornaviruses have been found in many warm-blooded animals but had never been implicated in human diseases before, according to the paper.

The researchers, led by a veterinarian at the Friedrich Loeffler Institute in Germany, could not determine how the virus spread from the squirrels to their handlers, nor could they say for certain the animals were to blame for the three deaths. But the evidence was compelling enough for them to conclude they have discovered a new "zoonotic illness," or a pathogen that can be spread from animals to people.

This report will likely add to rising concerns in the animal health community over diseases that can be passed from animals to people. The deadly Ebola outbreak in Africa earlier this year was tracked to bats in Guinea. And a study published in April described 20 diseases people can catch from household pets, including Salmonella, E. coli and roundworms.

A growing movement known as One Health is advocating better cooperation between human-health scientists and veterinarians in the effort to combat zoonotic illnesses. In March, Zoetis ($ZTS) promoted One Health at a conference in Amsterdam, where executives expressed concerns that more than 60% of infectious human diseases start in wild animals and 75% of emerging pathogens can be passed from animals to people.

- read more about the squirrel virus at Medpage Today
- here's the NEJM article