California resident diagnosed with plague

(Reuters) - A resident of South Lake Tahoe, California, has tested positive for plague, the state's first case of the highly infectious disease - known as the "Black Death" during the Middle Ages - in five years, health officials said on Tuesday.

El Dorado County health officials said in a statement that they suspected the person was bitten by the plague-infected flea while either walking their dog in the Tahoe Keys area or along the Truckee River Corridor in east-central California. Their investigation was still in progress.

Signs have been posted around South Lake Tahoe to warn of the presence of the plague and how to prevent exposure, they said.

Plague, which has three variants including bubonic, is a highly-infectious and often fatal disease caused by bacteria that is spread mostly by rodents. It can now be treated effectively with antibiotics if detected early, El Dorado health officials said.

"Plague is naturally present in many parts of California, including higher elevation areas of El Dorado County. 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. Human cases of plague are extremely rare but can be very serious," El Dorado County Public Health Officer Nancy Williams said in a statement.

The California resident was under professional medical care and recovering at home, health officials said.