A resident of South Lake Tahoe in California has tested positive for the plague, local authorities announced this week.
A statement released on Tuesday by health officials in El Dorado county said they were notified of the situation by the California department of public health (CDPH). The statement said the individual is now recovering at home and is under the care of a medical professional.
Health officials believe that the person “may have been bitten by an infected flea while camping in the South Lake Tahoe area”, a popular recreation spot in the California mountains, and said that they are investigating the situation.
“Plague is naturally present in many parts of California, including higher-elevation areas of El Dorado county,” said Kyle Fliflet, El Dorado county’s acting director of public health. “It’s important that individuals take precautions for themselves and their pets when outdoors, especially while walking, hiking and/or camping in areas where wild rodents are present.”
According to the news release, plague is caused by the bacterium Yersinia pestis, and is most often transmitted by the bites of fleas “that have acquired the bacteria from infected squirrels, chipmunks and other wild rodents”.
Dogs and cats can also carry infected fleas into the home, officials said.
In the statement, local officials advised the public to avoid contact with wild rodents and to prevent pets from going near rodent burrows.
The news release said that while human cases of plague are “extremely rare”, they can be very serious. Symptoms typically appear within two weeks of exposure and include fever, nausea, weakness and swollen lymph nodes, the release noted. If detected early, plague can be effectively treated with antibiotics.
CDPH said that it routinely monitors rodent populations across California for plague activity.
The department said that surveillance in El Dorado county from 2021 through 2024 identified a total of 41 rodents that showed evidence of exposure to the plague bacterium.
So far in 2025, four rodents have tested positive, county officials said, adding that they were all within the Tahoe Basin.
This week’s case is not the region’s first brush with plague. The last confirmed human case in El Dorado county was in 2020, the statement added, and was also believed to be linked to the South Lake Tahoe area. Before that, the release says that two cases were reported in 2015 after exposure in Yosemite national park. All individuals were treated and recovered.
In 2021, the US Forest Service announced it was closing several popular sites at Lake Tahoe for several days after discovering plague in the chipmunk population.
The federal agency said at the time that “vector control” workers would complete “eradication treatments” in the area.
Last year, Colorado health officials also confirmed a human case of the plague.
The Centers for Disease Control and Prevention estimates that there is an average of seven human plague cases a year in the US, with most of the human cases occurring in the western US.
