(CNN) -- Authorities in Riverside County, California, said Tuesday that a ground squirrel has tested positive for exposure to fleas infected with the bacteria that can cause plague.
It's the country's first positive test in more than a decade, according to Dottie Merki, environmental health program chief at the Riverside County Department of Environmental Health.
"It's not something that people should panic about, but we do want them to be educated so they can protect their families and their pets," she said.
The squirrel was picked up in early September at a campground north of Idyllwild, located in the San Jacinto Mountains in southern California.
Routine tests are done as plague is endemic to the area, said Merki. Authorities plan to conduct more tests this week, weather permitting, she said.
Plague is caused by the bacterium, Yersinia pestis.
Humans can get plague from handling an infected animal or from being bitten by a rodent flea carrying the bacterium, according to the Centers for Disease Control and Prevention.
Plague can cause serious illness or death, though modern antibiotics are effective in treating it if administered promptly, the CDC said.
Health officials in Riverside County stressed that the risk of transmission to humans is small, especially if people take the proper precautions. They offered the following advice:
-- Avoid contact with squirrels and other wild animals
-- Do not feed or touch wild animals
-- Do not touch dead animals
-- Do not rest or camp near animal burrows
-- Protect your pets by leaving them at home, or by keeping them on a leash and using flea-control methods.