California Resident Contracts Plague After Flea Bite at Lake Tahoe

A resident camping near South Lake Tahoe, California, has been diagnosed with the plague, marking the first human case in the state since 2020. The individual is currently recuperating at home while receiving medical treatment. Authorities from El Dorado County confirmed the case, noting that the patient was likely bitten by an infected flea during outdoor activities near the Nevada border. An investigation is ongoing to determine the source and extent of exposure.

Plague, caused by the bacterium Yersinia pestis, remains present in certain regions of California, especially in higher elevations like those in El Dorado County. The disease is primarily transmitted through fleas that acquire the bacteria from infected wild rodents such as squirrels and chipmunks. Handling infected animals or exposure to environments with wild rodents can also pose risks. Notably, dogs and cats can carry infected fleas, contributing to potential transmission.

Historically infamous for causing devastating pandemics in Europe centuries ago, modern medicine has made plague a treatable disease. When diagnosed early, symptoms such as fever, nausea, weakness, headache, and swollen lymph nodes can be effectively managed with common antibiotics.

Health officials advise residents and visitors to take preventive steps when outdoors in areas frequented by wild rodents. Recommendations include avoiding contact with dead or injured rodents, camping away from rodent carcasses, and using protective clothing and insect repellents to ward off fleas. Pet owners are encouraged to use effective flea control products and prevent pets from wandering in areas where they may encounter wild rodents.

Despite no recent human cases, ongoing surveillance reveals exposure evidence in local rodents, with 41 rodents testing positive between 2021 and 2024 and four in 2025 within the Tahoe basin. Authorities urge awareness and precaution to prevent further transmission.

For more detailed information about how plague spreads and prevention methods, visit the CDC's resources.

Source: https://medicalxpress.com/news/2025-08-california-resident-infected-plague-flea.html