El Dorado County Resident Tests Positive for Plague

South Lake Tahoe, CA…El Dorado County health officials have been notified by the California Department of Public Health (CDPH) that a South Lake Tahoe resident has tested positive for plague. The individual is currently under the care of a medical professional and is recovering at home. It’s believed that the person, an avid walker, may have been bitten by an infected flea while walking their dog along the Truckee River Corridor north of Highway 50 or the Tahoe Keys area in South Lake Tahoe. Health officials are investigating the situation.

According to El Dorado County Public Health Officer, Dr. Nancy Williams, “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.” Several areas of South Lake Tahoe have signs posted to advise the public of the presence of plague and ways to prevent exposure.

Plague is caused by the bacterium, Yersinia pestis. Plague bacteria are most often transmitted by the bites of fleas that have acquired the bacteria from infected squirrels, chipmunks and other wild rodents. Dogs and cats may also bring plague-infected fleas into the home. People can get plague when they are bitten by infected fleas. Plague can be prevented by avoiding contact with wild rodents, and by keeping pets away from rodent burrows.

Symptoms of plague usually show up within two weeks of exposure to an infected animal or flea and include fever, nausea, weakness and swollen lymph nodes. Plague can be effectively treated with antibiotics if detected early.

CDPH routinely monitors rodent populations for plague activity in California and closely coordinates with county health officials. Surveillance activities in El Dorado County from 2016 to 2019 found a total of 20 rodents (ground squirrels or chipmunks) with evidence of exposure to the plague bacterium. These rodents were identified in the South Lake Tahoe area, at or near the Tallac Historic Site, Fallen Leaf Campground and/or Taylor Creek Visitor Center. There were no recent reports of plague-associated illness to people in El Dorado County prior to the current case. The last reported cases of plague in California were two human cases which were exposed to infected rodents or their fleas in Yosemite National Park in 2015. Both people were treated and recovered. These were the first reported human cases in the state since 2006.

Tips to prevent plague include the following:

Do not feed squirrels, chipmunks or other wild rodents.
Never touch sick, injured or dead rodents.
Do not allow your pets to play with or pick up sick, injured or dead rodents.
Do not camp, sleep or rest near animal burrows or areas where dead rodents are observed.
Look for and heed posted warning signs.
Wear long pants tucked into boot tops and spray insect repellent containing DEET on socks and pant cuffs to reduce exposure to fleas.
Leave pets home if possible; otherwise keep pets on a leash. Do not allow pets to approach sick or dead rodents or explore rodent burrows.
Protect pets with flea control products.
Pet cats are highly susceptible to plague and can pose a direct threat to humans. Keep cats away from rodents. Consult a veterinarian if your cat becomes sick after being in contact with rodents.
If you get sick after being in an area where plague is known to occur, consult a physician and tell them you may have been exposed to plague.

State and local health officials will continue to monitor the situation and any plague-prone areas. To report a sick or dead rodent or for questions about plague, please contact El Dorado County Environmental Management at (530) 573-3450. For more information about plague, visit the CDPH website at:

https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/Plague.aspx