A resident of South Lake Tahoe in California has tested positive for the plague, local authorities announced this week.

On Tuesday, health officials in El Dorado County disclosed that they had been alerted by the California Department of Public Health (CDPH) about a recent incident. The individual affected is reported to be recuperating at home under medical supervision.

Officials suspect that the individual might have contracted the infection from a flea bite during a camping trip in the South Lake Tahoe region, a favorite mountain getaway in California, and investigations are underway to confirm this.

“Plague is a naturally occurring disease in many regions of California, especially in high-altitude zones of El Dorado County,” explained Kyle Fliflet, the acting public health director. “When spending time outdoors, particularly around areas inhabited by wild rodents, it’s crucial for people and their pets to take necessary precautions.”

The news release describes plague as a disease caused by the bacterium Yersinia pestis, usually spread through flea bites. These fleas typically acquire the bacteria from infected wild rodents like squirrels and chipmunks.

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.

Although human cases of plague are “extremely rare,” the news release stressed that they can be severe. Symptoms generally manifest within two weeks of exposure and include fever, nausea, weakness, and swollen lymph nodes. Early detection allows for successful treatment with antibiotics.

CDPH said that it routinely monitors rodent populations across California for plague activity.

The department noted that from 2021 to 2024, surveillance in El Dorado County found 41 rodents with signs of plague exposure.

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.