A person has tested positive for plague after possibly being bitten by an infected flea while camping in the South Lake Tahoe area of California, public health officials say.
El Dorado County’s Public Health Division announced the positive plague case Tuesday, noting that the person was recovering at home under medical care.
An investigation into the exact circumstances of the plague infection is underway.
“Plague is naturally present in many parts of California, including higher elevation areas of El Dorado County,” said Kyle Fliflet, acting director of public health for the county. “It’s important that individuals take precautions for themselves and their pets when outdoors, especially while walking, hiking, or camping in areas where wild rodents are present.”
Plague, caused by the bacterium Yersinia pestis, is typically spread by fleas that have fed on infected wild rodents such as squirrels and chipmunks, health officials said. Pets, particularly cats and dogs, can also carry plague-infected fleas into the home.
Plague symptoms
Symptoms of plague generally appear within two weeks of exposure and may include fever, nausea, weakness, and swollen lymph nodes. If detected early, the illness is treatable with antibiotics.
Although human cases of plague are extremely rare, they can be serious. El Dorado County said this is its first reported human case since 2020. Prior to that, the last confirmed cases in California were in 2015, involving two people exposed in Yosemite National Park. All previous patients recovered after receiving treatment.
Surveillance conducted by the California Department of Public Health (CDPH) and local health agencies between 2021 and 2024 identified 41 rodents in El Dorado County that had been exposed to plague. In 2025, four additional rodents have tested positive—each found in the Tahoe Basin.
El Dorado County Public Health shared the following tips to prevent exposure:
Avoid contact with squirrels, chipmunks, or other rodents.
Do not allow pets to interact with sick or dead rodents.
Use flea control products on pets and keep them leashed when outdoors.
Wear long pants and use insect repellent containing DEET when hiking or camping.
Be aware of all posted warning signs.
Seek medical attention if you experience symptoms after visiting an area known for plague activity.