A California resident has tested positive for plague after likely being bitten by an infected flea, health officials said on Tuesday, Aug. 19.

The person was camping in the South Lake Tahoe area, located in the Sierra Nevada mountains in eastern California, the El Dorado County Public Health Division (EDCPHD) said in a statement. This is the first such infection reported in the county since 2020, when a case of human plague was also traced back to the South Lake Tahoe area, the public health division added.

The resident is recovering at home under the supervision of a medical professional.

Plague is caused by the bacterium Yersinia pestis and is most often transmitted to humans and other mammals via flea bites or handling infected animals. Rodent fleas spread the bacteria to people, dogs and cats after becoming infected by squirrels, chipmunks and other wild rodents.

An average of seven people are diagnosed with a confirmed case of the plague each year in the United States, according to the U.S. Centers for Disease Control and Prevention, predominantly in the western part of the country. Typically, cases occur in northern New Mexico, northern Arizona, southern Colorado, California, southern Oregon, and far western Nevada. Over 80% of U.S. plague cases have been the bubonic form, also known as the "black plague," said the CDC.

While the bubonic plague is famous for killing huge swathes of the European population during the Middle Ages, it is now treatable with antibiotics.

“Plague is naturally present in many parts of California, including higher elevation areas of El Dorado County," Kyle Fliflet, El Dorado County’s acting director of public health, said in a statement. “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."

Health officials are investigating the situation, said EDCPHD.

Symptoms of plague and how to protect yourself

The three different types of plague — bubonic, septicemic and pneumonic — have some differing symptoms, though many of the fundamental signs are the same.

According to the CDC and EDCPHD, symptoms of the most common form of plague in the United States, bubonic, appear within two weeks of exposure and include:

  • Fever
  • Headache
  • Chills
  • Nausea
  • Weakness
  • Swollen lymph nodes

To protect yourself from the small − yet real − chance of contracting plague, the agencies suggest:

  • Do not feed squirrels, chipmunks or other wild rodents. Reduce rodent habitat around your home, workplace, and recreational areas by removing brush, rock piles, junk, cluttered firewood and possible rodent food supplies.
  • Never touch sick, injured or dead rodents. Wear gloves if you are handling or skinning potentially infected animals.
  • Do not allow your pets to play with or pick up sick, injured or dead rodents. Use flea control products to protect them from bites.
  • Do not camp, sleep or rest near animal burrows or areas where dead rodents are observed.
  • Wear long pants tucked into boot tops and spray insect repellent containing DEET (a chemical compound common in commercial insect repellents) on socks and pant cuffs to reduce exposure to fleas.
  • 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.

This article originally appeared on USA TODAY: California resident tests positive for plague after camping in South Lake Tahoe

Reporting by Mary Walrath-Holdridge, USA TODAY / USA TODAY

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