Three campgrounds in the Los Angeles National Forest in California are closed after park personnel caught a flea-ridden squirrel infected with plague. According to ABC News, Los Angeles County Health Department officials say the campground will be closed for at least a week while investigators test squirrels and other animals in the park to get an idea of the scope of the outbreak.

L.A. County health officer Dr. Jonathan Fielding told NBC News, "We found [a squirrel] that had plague, the blood showed exposure to plague and it had something like 12 fleas on it."

He said in a statement, "Plague is a bacterial infection that can be transmitted to humans through the bites of infected fleas, which is why we close affected campgrounds and recreational areas as a precaution while preventive measures are taken to control the flea population."

Plague, which ravaged Europe in cycles during the Middle Ages, is caused by the microorganism Yersinia pestis, which manifests in three forms in the human body, bubonic, pneumonic and septicemic plague. Bubonic plague is named for the black, pus-filled boils -- called buboes -- that appear in the groin, armpits and other locations. Pneumonic plague attacks the lungs and drowns the victim in their own fluids. Septicemic plague attacks the circulatory system, causing severe stomach pain; bleeding from the nose, mouth and rectum; high fever and tissue necrosis.

However, said Fielding, “It is important for the public to know that there have only been four cases of human plague in Los Angeles County residents since 1984, none of which were fatal.”

Plague infections, if caught early, can be managed by antibiotics. Nonetheless, officials closed three areas of the Table Mountain Campgrounds as a precaution.

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[image of a squirrel on a tree via]