A popular campground at Yosemite National Park is closed this week after officials confirmed at least two squirrels found dead in the campground died of plague. California Department of Public Health officials say Tuolumne Meadows Campground in Yosemite will be closed to the public for five days, beginning Monday and through Friday, so officials can try to eradicate the disease by treating rodent burrows for fleas.
“Although this is a rare disease, and the current risk to humans is low, eliminating the fleas is the best way to protect the public from the disease,” Dr. Karen Smith, director of the CDPH, said in a statement. “By eliminating the fleas, we reduce the risk of human exposure and break the cycle of plague in rodents at the sites. People can protect themselves from infection by avoiding any contact with wild rodents,” she said.
The closure of the campground comes after a child who had been camping at Yosemite’s Crane Flat Campground, about 40 miles away, tested positive for the plague earlier this month. The child, who is from Southern California, and has not been named, is recovering. Crane Flat Campground, which was closed after the incident, has since been reopened. Health officials say no other people who were camping with the child became sick.
Health officials say plague is an infectious bacterial disease that is carried by squirrels, chipmunks and other wild rodents and their fleas. When an infected rodent becomes sick and dies, its fleas can carry the infection to other warm-blooded animals including humans.
Early symptoms of the disease may include high fever, chills, nausea, weakness and swollen lymph nodes in the neck, armpit or groin. People who develop these symptoms should seek immediate medical attention and notify their healthcare provider that they have been camping or out in the wilderness and have been exposed to rodents and fleas.
In California, health officials say plague-infected animals are most likely to be found in the foothills and mountains and to a lesser extent, along the coast. State and local health officials regularly monitor plague-prone areas by testing animals and their fleas. Last year, non-human plague activity was detected in animals in seven California counties: El Dorado, Mariposa, Modoc, Plumas, San Diego, Santa Barbara, and Sierra.
Health officials say before the child became sick with the plague this summer the last reported cases of human plague in California occurred in 2005 and 2006 in Mono, Los Angeles and Kern counties. All three patients survived following treatment with antibiotics. Yosemite Park officials say the last case of plague associated with exposure in the park was in 1959.
Plague is not transmitted from human to human unless a patient with plague also has a lung infection and is coughing.