Last October, Grand Canyon biologist Eric York found a female mountain lion he'd been tracking dead, with no evidence of injury other than a trail of blood leaking from her nose. Curious about the death, he took her to his garage to perform a postmortem; by Nov. 2, York was dead at age 37 from pneumonic plague.
Somehow, York must've released the plague bacteria, which then made the leap to humans. While York came into contact with 49 people, luckily no one else got infected. So far, no epidemic plague outbreaks have happened in the Grand Canyon area, but national park and CDC scientists are now working together to monitor and identify diseases throughout the park system to prevent any potential outbreaks.
60 percent of epidemics begin when bacteria or viruses make an interspecies jump; death rates for pneumonic plague victims can be as high as 50 percent.
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