Something new to worry about in California: Black Death Squirrels

A ground squirrel recently found in Southern California's Angeles National Forest has tested positive for plague.

Authorities have evacuated and shut down an area of the national forest near Los Angeles for at least one week, county public health officials said Thursday.

From Reuters:
Health officials said that as a precaution, visitors were ordered to leave three campgrounds and a recreation area of the Angeles National Forest, which encompasses some 655,000 acres in the San Gabriel Mountains just north of metropolitan Los Angeles. Plague, known as the "Black Death" when it was blamed for killing some 25 million Europeans during the Middle Ages, is a bacterial infection that can be transmitted to humans through the bites of infected fleas. A health department spokesman said no people were believed to have been infected. "It is important for the public to know that there have only been four cases of human plague in Los Angeles County residents since 1984, none of which were fatal," the health department chief, Dr. Jonathan Fielding, said in a statement.

Here's the LA County Department of Public Health's PDF factsheet on plague vectors.