Case Reported in South Lake Tahoe
Health officials in El Dorado County, California, confirmed that a South Lake Tahoe resident has tested positive for the plague. The individual is currently recovering at home under medical supervision. Authorities believe the infection likely resulted from a flea bite while camping in the area, a popular outdoor recreation destination.
Plague Transmission and Precautions
Plague is caused by the bacterium Yersinia pestis and is usually spread through the bites of fleas that have fed on infected rodents, such as squirrels and chipmunks. Dogs and cats can also carry infected fleas into homes.
El Dorado County officials advise the public to avoid contact with wild rodents and keep pets away from rodent burrows. Symptoms in humans can appear within two weeks and include fever, nausea, weakness, and swollen lymph nodes. When detected early, plague is treatable with antibiotics.
Surveillance and Previous Cases
The California Department of Public Health (CDPH) monitors rodent populations for plague activity. From 2021 to 2024, 41 rodents in El Dorado County showed evidence of exposure. In 2025, four rodents tested positive, all within the Tahoe Basin.
Human cases in the region are rare. The last confirmed case in El Dorado County occurred in 2020, also linked to South Lake Tahoe. Prior cases in the area include two exposures in Yosemite National Park in 2015. All affected individuals were treated successfully.
Regional and National Context
In 2021, the US Forest Service temporarily closed several Lake Tahoe sites after detecting plague in chipmunks and carried out vector control measures. Colorado also reported a human case in 2024.
According to the CDC, the United States averages seven human plague cases per year, with most occurring in western states. Officials stress the importance of caution when hiking, camping, or spending time outdoors in areas where wild rodents are present.
