According to the California Department of Public Health (CDPH), a child from Los Angeles County became ill and was hospitalized after visiting Yosemite National Park in mid-July. No other members of the camping party reported symptoms and health officials are continuing to monitor the child’s family and treatment providers. The child is recovering.

The last reported cases of human plague in California occurred in 2005 and 2006 in Mono, Los Angeles and Kern counties and all three patients survived following treatment with antibiotics. Since 1970, 42 human cases of plague have been confirmed in California, of which nine were fatal.

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 or humans.

“Human cases of plague are rare, with the last reported human infection in California occurring in 2006,” Dr. Smith said. “Although this is a rare disease, people should protect themselves from infection by avoiding any contact with wild rodents.

Early symptoms of plague 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 health care provider that they have been camping or out in the wilderness and have been exposed to rodents and fleas. Plague is treatable in its early stages with prompt diagnosis and proper antibiotic treatment. If not treated, plague can be fatal.