The California Department of Public Health is investigating a possible second case of human plague contracted by a tourist who recently visited Yosemite National Park, less than two weeks after announcing that a child who camped at a Yosemite campground had the disease.
CDPH Director Karen Smith said the department had been notified of a presumptive positive case of plague in a person visiting California from Georgia. The Centers of Disease Control and Prevention is conducting testing to confirm the case, Smith said. Before falling ill, the patient traveled to Yosemite, the Sierra National Forest and surrounding areas in California in early August.
On Aug. 6, health officials announced they were investigating a case of human plague after a child contracted the rare disease while camping in Yosemite's Crane Flat Campground. The last reported human plague case occurred in California in 2006.
Although park officials confirmed the plague was in squirrels over the past two weeks at Crane Flat and Tuolumne Meadows campgrounds in Yosemite, the risk to human health remains low, health officials said. Both campgrounds were closed as a caution, but the rest of the park remains open.
Park officials are also notifying visitors of camp treatments, possible plague risks and information on how to prevent transmission.
"CDPH and Yosemite National Park were very proactive in their campaign to educate visitors about plague," Smith said. "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."
Yosemite has also been carrying out flea treatment to reduce the risk of plague transmission at Crane Flat and Tuolumne Meadows campgrounds.
Plague is an infectious bacterial disease that is carried by squirrels, chipmunks and other wild rodents, along with their fleas. When an infected rodent becomes sick and dies, its fleas can carry the infection to other warm-blooded animals including humans.
The California plague announcements come after Colorado health officials said an adult had succumbed to the plague in Colorado – the second in the state this year – after likely "contracting the disease from fleas on a dead rodent or animal."
Steps the public can take to avoid exposure to human plague include:
• Never feed squirrels, chipmunks or other rodents and never touch sick or dead rodents.
• Avoid walking or camping near rodent burrows.
• Wear long pants tucked into socks or boot tops to reduce exposure to fleas.
• Spray insect repellent containing DEET on skin and clothing, especially socks and pant cuffs to reduce exposure to fleas.
• Keep wild rodents out of homes, trailers, and outbuildings and away from pets