"FORT COLLINS, Colo. -- Sylvatic plague -- a close cousin of the dreaded disease that killed one-third of all European residents in the six years between 1347 and 1353 -- persists in rodents in the American West even when the disease does not erupt into epidemic form, new research demonstrates.

The newly published work indicates that plague continues to affect the black-footed ferret, one of the most critically endangered mammals in North America, as well as several species of prairie dogs, including the federally threatened Utah prairie dog.

The disease also has been found in larger predators such as cougars and lynx that prey on rodents, rabbits, chipmunks and squirrels that may be susceptible to plague.

Plague, a flea-borne disease caused by the bacterium Yersinia pestis was introduced to North America in the late 1800s. It spreads rapidly, causing devastating effects to wildlife and posing risks to people."

Environment News Service had the story March 1, 2010. [2]