Watch CBS News

California confirms first case of plague in 5 years

Squirrel tests positive for plague in Colorado
Squirrel tests positive for bubonic plague in Colorado 01:09

Health officials have confirmed a case of plague at South Lake Tahoe — the first in California in five years. El Dorado County officials said Monday that the California Department of Public Health notified them of the positive test of a local resident who is under medical care while recovering at home.

Plague bacteria are most often transmitted by fleas that have acquired it from infected squirrels, chipmunks and other wild rodents. Dogs and cats may also carry plague-infected fleas.

Health officials believe the South Lake Tahoe resident may have been bitten by an infected flea while walking a dog along the Truckee River corridor or in the Tahoe Keys area on Tahoe's south shore.

"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," said El Dorado County Public Health Officer, Dr. Nancy Williams. "Human cases of plague are extremely rare but can be very serious."

The last reported human cases of plague in California were in 2015 when two people were exposed to infected rodents or their fleas in Yosemite National Park. Both were treated and recovered.

No human cases have been reported since, but authorities did find evidence that a total of 20 ground squirrels or chipmunks around South Lake Tahoe had been exposed to the plague bacterium from 2016-19. Those rodents were identified near the Tallac Historic Site, Fallen Leaf Campground or Taylor Creek Visitor Center.

Symptoms and prevalence of the plague

Symptoms include fever, nausea, weakness, and swollen lymph nodes and usually show up within two weeks of initial contact with an infected animal. The disease can be treated with antibiotics, but if it's not caught early, can turn deadly.

The disease killed millions of people in Europe in the Middle Ages in a series of outbreaks known as the Black Death. However, now it is very rare, especially in the U.S.

According to the Centers for Disease Control and Prevention, in recent decades, an average of seven human plague cases are reported nationwide each year. Most human cases in the United States are scattered in rural areas in the west, including northern New Mexico, northern Arizona, southern Colorado, California, southern Oregon, and far western Nevada.

View CBS News In
CBS News App Open
Chrome Safari Continue
Be the first to know
Get browser notifications for breaking news, live events, and exclusive reporting.