A South Lake Tahoe resident in California has tested positive for the plague, according to local authorities. The case was confirmed this week by the California Department of Public Health (CDPH), which alerted El Dorado County health officials.
The individual is now recovering at home under medical supervision, officials said. Preliminary investigations suggest that the person may have contracted the infection from a flea bite while camping in the South Lake Tahoe area, a beloved destination in California’s mountain region. Authorities continue to probe the circumstances of the case.
“Plague is naturally present in many parts of California, including higher-elevation areas of El Dorado County,” said Kyle Fliflet, the county’s acting public health director. “People should take precautions for themselves and their pets when outdoors, especially while hiking, camping, or walking in areas where wild rodents live.”
The plague, caused by the bacterium Yersinia pestis, is most often transmitted through the bites of fleas that have fed on infected squirrels, chipmunks, or other wild rodents. Pets can also carry infected fleas into homes, increasing the risk of exposure. Health officials advise the public to avoid contact with wild rodents and keep animals away from rodent burrows.
While human plague cases are extremely rare, they can be severe. Symptoms typically appear within two weeks of exposure and include fever, nausea, fatigue, and swollen lymph nodes. Early detection is critical, as the infection can be successfully treated with antibiotics.
CDPH conducts routine monitoring of rodent populations across California for signs of plague. Between 2021 and 2024, surveillance in El Dorado County identified 41 rodents that tested positive for exposure to the bacterium. In 2025 alone, four rodents, all within the Tahoe Basin, have already tested positive.
This is not the region’s first encounter with plague. The last human case in El Dorado County occurred in 2020 and was similarly linked to South Lake Tahoe. Previously, two cases were reported in 2015 after exposure in Yosemite National Park. All affected individuals were treated successfully and recovered.
Public health concerns have occasionally prompted action in the area. In 2021, the US Forest Service temporarily closed several Lake Tahoe sites after detecting plague among chipmunks. Vector control teams carried out targeted eradication treatments to limit the risk of transmission.
Plague is not confined to California. Colorado health officials reported a human case last year, highlighting that the disease, though rare, remains present in parts of the western United States. According to the Centers for Disease Control and Prevention (CDC), the US sees an average of seven human plague cases annually, most of them in western states.
