Squirrel breeding is a real job—and apparently a very dangerous one if you're dealing with the wrong kind of squirrel. After the mysterious deaths of three German men who all worked as breeders of variegated squirrels—a kind of squirrel native to Central America that's sometimes kept as an exotic pet—researchers have identified a new virus that had apparently jumped from the squirrels to the men, LiveScience reports.

The men, who were in their 60s and regularly socialized together, died between 2011 and 2013 from inflammation of the brain, and researchers say at least two of them had been scratched or bitten by the squirrels.

They died a few months after showing symptoms, including fever and weakness. The virus found in the men is a new bornavirus, a kind of virus often found in horses and sheep, according to a study published in the New England Journal of Medicine.

The European Center for Disease Prevention and Control suggests avoiding direct contact with variegated squirrels—which should be pretty easy for most people—and a professor of medicine at NYU Langone Medical Center tells HealthDay that there's no need to fear a major squirrel-borne outbreak.

"It is possible that this virus could spread to squirrels here in the US and occasionally to humans, but we wouldn't see sustained spread, as there is no evidence of spread from human to human," he says.

(A bite from a rabid fox led researchers to a new strain of rabies.)

This article originally appeared on Newser: Deadly New Virus Jumped From Squirrels to People

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