Sacramento, California - California Department of Public Health (CDPH) Director and State Health Officer Dr. Karen Smith announced that the department has been notified of a presumptive positive case of plague contracted by a recent visitor to California from Georgia. Confirmatory testing is being conducted by the Centers for Disease Control and Prevention (CDC). Prior to becoming ill, the patient had been vacationing in Yosemite National Park (Yosemite), the Sierra National Forest and surrounding areas in California in early August.

CDPH is in contact with Yosemite, CDC and the National Forest Service to assess locations where the patient visited.

Plague is an infectious bacterial disease that is carried 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.

Although the presence of plague has been confirmed in wild rodents over the past two weeks at Crane Flat and Tuolumne Meadows campgrounds in Yosemite, the risk to human health remains low. Action to protect human and wildlife health by closing and treating campgrounds was taken out of an abundance of caution. Park visitors are being notified by Yosemite of camp treatments, possible plague risks and are being provided information on how to prevent plague transmission. CDC has notified CDPH that recent communications about plague enabled health care providers in Georgia to make the diagnosis more quickly.

“The California Department of Public Health and Yosemite National Park were very proactive in their campaign to educate visitors about plague,” said Dr. Smith. “Warnings issued in California regarding plague were useful all the way across the country in Georgia. Those warnings helped the patient get the prompt medical attention necessary to recover from this illness.”

Flea treatment successfully reduced the risk of plague transmission at Crane Flat Campground and Tuolumne Meadows Campground in the National Park. The treatments controlled potentially plague-infected fleas which could spread the disease to humans and other warm-blooded hosts. Yosemite National Park remains open and all campgrounds and facilities, except Tuolumne Meadows, remain open to visitors. CDPH reminds the public to take protective measures against the illness.