July 17, 2006 - (SACRAMENTO) - Summer visitors to rural picnic spots, campgrounds and wilderness areas should take precautions to protect themselves from plague, a disease carried by rodents, State Public Health Officer Dr. Mark Horton advised today.

"Individuals can greatly reduce their risk of becoming infected with plague by taking simple precautions, including avoiding contact with wild rodents," Horton said.  "Do not feed rodents in picnic or campground areas and never handle sick or dead rodents.  Also, leave your pets at home when visiting rural areas."

The most recent cases of plague in California occurred in June in a woman from Mono County, in April in a woman from Los Angeles County and in November 2005 in a man from Kern County.  All three patients survived following treatment with antibiotics.  Since 1970, 42 cases of plague have been confirmed in humans in California.

Plague is a highly infectious bacterial disease that is spread by squirrels, chipmunks and other wild rodents and their fleas.  When an infected rodent becomes sick and dies, its fleas can carry the infection to other warm-blooded animals, including humans.  People also can be exposed through contact with infected cats, which are highly susceptible to the disease.

Early symptoms of plague include high fever, chills, nausea, weakness and swollen lymph nodes in the neck, armpit or groin.  Individuals who develop these symptoms should seek immediate medical attention.  Plague is curable in its early stages with prompt diagnosis and proper treatment, but may be fatal if not treated.

In California, plague-infected animals are most likely to be found in the foothills, mountains and along the coast.  Desert and Central Valley areas are considered low risk for plague.  To date in 2006, plague activity has been detected in animals in Inyo, Kern, Mariposa, Mono, Plumas and Sierra counties.

State and local health officials regularly monitor plague-prone areas.  If sick and dying rodents or other evidence of plague are observed and the risk of transmission to humans is judged to be high, affected areas may be temporarily closed to protect the public and to implement control measures.  Other precautions against exposure to plague offered by Horton include:

·         Avoid walking, hiking or camping near rodent burrows.

·         Wear long pants tucked into boot tops to reduce exposure to fleas. 

·         Spray insect repellent containing DEET on socks and trouser cuffs.

·         Individuals living in areas where plague is known to occur should keep wild rodents out of homes, trailers and outbuildings and away from pets.

Return to Other Environmental Health News