Plague in California Sparks Health Alert as Rare Case Confirmed in South Lake Tahoe

A South Lake Tahoe resident in California has been confirmed to have contracted the plague, health officials have disclosed. The individual, now recuperating at home under medical supervision, is believed to have been bitten by an infected flea during a camping trip in the area. The El Dorado County health department, which was notified by the California Department of Public Health, is currently investigating the circumstances surrounding this case.

The plague, an infectious disease caused by the bacterium Yersinia pestis, is commonly transmitted by fleas that have fed on infected rodents such as squirrels and chipmunks. Health authorities caution that pets, notably dogs and cats, can also carry infected fleas indoors, posing a risk to humans. Despite the potential for serious health implications, the disease is exceptionally rare in humans, with symptoms such as fever, nausea, weakness, and swollen lymph nodes typically manifesting within two weeks of exposure. Early diagnosis and treatment with antibiotics is crucial for recovery.

Public health officials note that while the plague is rare, it naturally exists in several regions across California, including the higher-elevation areas within El Dorado County. The most recent case in the region was reported in 2020. Prior to that, two incidents were linked to exposure in Yosemite National Park in 2015. Over the years, rodent surveillance efforts have detected numerous occurrences of plague bacteria among local wildlife populations. Between 2021 and 2024, 41 rodents tested positive for exposure to the plague bacterium, with an additional four positive cases recorded within the Tahoe Basin in 2025.

Officials recommend preventative measures for individuals venturing into areas with wild rodent populations, particularly when engaging in outdoor activities like walking, hiking, or camping. Precautionary actions include avoiding contact with wild rodents, including squirrels and chipmunks, not approaching dead or injured animals, and using protective measures such as insect repellents and proper clothing to prevent flea bites. Pet owners are advised to prevent their animals from accessing rodent burrows and to use flea control products consistently.

Reflecting on historical data, the Centers for Disease Control and Prevention (CDC) have observed that most human plague cases in the United States occur in western states. The CDC estimates an average of seven human plague cases nationally each year, underscoring the importance of awareness and prevention in endemic areas.

Local health officials continue to monitor and manage the situation diligently to mitigate further risks to the public while reinforcing the importance of precautionary health practices in areas where the plague could naturally occur.