A resident in California's popular vacation destination of Lake Tahoe has tested positive for the Black Death, a rare but serious bacterial infection. The unidentified individual, from El Dorado County, is believed to have contracted the plague after being bitten by an infected flea while camping. California health officials confirmed that the patient is recovering at home under medical care.

This marks the first confirmed case of plague in El Dorado County since 2020, which was also thought to have originated in the South Lake Tahoe Area. Prior to that, the disease had not been detected in California since 2015. Nationwide, plague cases are rare, with the CDC reporting an average of just seven cases in the US each year. The most recent US case before this California incident was in Colorado last month, which unfortunately resulted in the patient's death.

Plague, also historically known as the Black Death, is an infectious disease caused by the bacterium Yersinia pestis. This bacterium is typically carried by fleas and transmitted between small mammals, particularly rodents. Regions like California and New Mexico are more prone to plague due to a higher prevalence of rodents susceptible to Yersinia pestis.

Historically, the Black Death ravaged Europe between 1347 and 1351, wiping out an estimated 25 to 50 million people, accounting for 30 to 50 percent of the continent's population. Today, thanks to modern antibiotics and improved hygiene, deaths from plague have been drastically reduced, though the disease remains endemic in wildlife in several countries, including parts of Africa, Asia, South America, and the US.

Symptoms of plague typically appear within one to eight days after infection. These can include a sudden onset of fever, chills, debilitating fatigue, head and body aches, weakness, vomiting, and nausea. A distinctive and often painful symptom is the swelling of lymph nodes, known as buboes, which commonly appear in the groin or armpits. This form is known as bubonic plague, the most common type.

If left untreated, the plague can rapidly progress. The bacteria can enter the bloodstream, causing septicemic plague, which leads to bleeding under the skin that can turn dark or black in certain spots. The infection can also travel to the lungs, resulting in pneumonic plague, the most dangerous form. Pneumonic plague can spread through inhaling droplets of saliva from an infected person or animal coughing or sneezing, and if untreated, it has a nearly 100 percent mortality rate. The overall mortality rate for untreated plague in the US is 30 to 60 percent. Once the disease enters cells, it releases deadly toxins, killing them.

Recent cases beyond California highlight the ongoing presence of plague. Last month, Arizona recorded its first plague death since 2007, attributed to pneumonic plague. Colorado and New Mexico also reported cases last year, with the New Mexico patient being the first to die from the plague there since 2020, and Colorado's first death since 2007.

Health officials strongly urge the public to take precautions, especially when outdoors in areas where wild rodents are present. El Dorado County acting director of public health, Kyle Fliflet, emphasized that plague is naturally present in higher-elevation areas of the county. Recommended preventive measures include avoiding exposure to rodents and their fleas, wearing long pants tucked into boots, using insect repellent with DEET, never feeding or touching wild rodents, and refraining from camping near animal burrows or dead rodents. From 2021 to 2025, the California Department of Health found evidence of plague exposure in 45 ground squirrels or chipmunks within the Lake Tahoe Basin, underscoring the local risk.