Health officials in El Dorado County are reminding residents and visitors that chipmunks, squirrels and other wild rodents can carry plague, and that a few simple precautions can prevent the spread of the disease.

The California Department of Public Health routinely monitors rodent populations for plague activity in California and closely coordinates with county health officials. So far this year, no rodents in El Dorado County have tested positive for plague. However, last year one rodent tested positive for the disease and three tested positive in 2013 in El Dorado County. The four positive rodents were all located in the Tahoe area. There were no reports of illness to people.

A campground in Yosemite was temporarily closed this month when visitors were diagnosed with plague.

Plague is an infectious bacterial disease spread by squirrels, chipmunks and other wild rodents and their fleas. People can get infected through close contact with infected animals or the bite of an infected flea. Plague can be prevented by avoiding contact with rodents and areas where fleas are noted, and by keeping pets away from rodent burrows.

Symptoms of plague usually occur 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.

Tips to prevent plague include:

• Do not feed squirrels, chipmunks or other wild rodents.
• Never touch 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.
• Cats can pose a higher risk of plague transmission to humans when they have contact with infected rodents. Keep cats away from rodents. Consult a veterinarian if your cat becomes sick after being in contact with rodents.