A California resident has tested positive for the plague after camping near Lake Tahoe, local health officials confirmed. It’s the latest in a string of positive cases in the western U.S. this year.

The infected person was likely bitten by a plague-infected flea in the South Lake Tahoe area, according to local health officials. This is the first local case in the area since 2020. The person is currently recovering and is undergoing medical treatment at home.

“Plague is naturally present in many parts of California, including higher elevation areas of El Dorado County,” Kyle Fliflet, acting director of public health in El Dorado County, in northern California, said in a statement.

“It’s important that individuals take precautions for themselves and their pets when outdoors, especially while walking, hiking and or camping in areas where wild rodents are present,” he said.

Plague is rare in the U.S., according to the Centers for Disease Control (CDC), affecting seven people in the U.S. per year, mostly in western states.

The disease is endemic in many California counties and other parts of the western U.S., where it circulates among wild rodents and other animals. Earlier this month, a cat in Colorado tested positive for the plague. Last month, an Arizona man died after contracting the disease. That person developed a pneumonic form of the plague, in which the bacterium spreads to the lungs, due to an untreated bubonic infection.

The disease is caused by the bacterium Yersinia pestis and is most commonly spread to humans by bites from infected fleas. It can be treated with antibiotics but can be fatal if not treated promptly. Infamously, the plague decimated Europe’s 14th-century population.

More than 80% of plague cases in the U.S. have been in the bubonic form, from which patients will develop swollen, painful lymph nodes called buboes, according to the CDC.

Like many other diseases caused by microbes, the plague is more likely now due to climate change, and cases have been steadily growing since the 1950s. But it’s still rare. The risk to the public of exposure as well as the risk of human-to-human transmission remains low, according to health officials.