El Dorado County health officials are advising the public to be cautious around chipmunks and squirrels due to increased plague activity in the Lake Tahoe Basin area in the fall.

In September and October, a surveillance effort identified three chipmunks as positive for plague in the South Lake Tahoe area; two were found near the U.S. Forest Service Taylor Creek Visitor Center and one was found near the Tallac Historic Site, according to a press release. There were no reports of illness to people. Signs were posted in the areas to alert the public, and individuals were advised to report dead or sick rodents. Signs will continue to be posted to alert the public, the release stated.

Plague is an infectious bacterial disease that is spread by squirrels, chipmunks and other wild rodents and their fleas. People can become infected through close contact with infected animals or the bite of an infected flea, health department officials stated. Plague can be prevented by avoiding contact with these rodents and their fleas, and by keeping pets away from rodents and their burrows. Human cases of plague are rare. 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.

State and local health officials will continue to monitor plague-prone areas. To report a sick or dead rodent or for questions about plague, contact El Dorado County Environmental Management at 530-573-3450. For more information about the plague, visit http://tinyurl.com/EDCplague.