California health officials investigating second case of plague this summer

A bite from this type of flea, commonly found on rock squirrels in the western U.S., can pass plague to humans.
A bite from this type of flea, commonly found on rock squirrels in the western U.S., can pass plague to humans.
John Montenieri/CDC

California health officials said Tuesday they're working to confirm a second case of plague, just two weeks after announcing a visitor to Yosemite National Park came down with the disease. That case was the first in the state in nine years.

The victim this time was a visitor from Georgia who had recently vacationed at Yosemite, as well as the Sierra National Forest and nearby campgrounds, California Department of Public Health officials said. In a statement, the department said it's working closely with forest and national parks officials to determine exactly where the infected visitor had stayed.

CDPH said

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. 

As KPCC's Rebecca Plevin reported two weeks back, plague — a strain of which was once responsible for a pandemic wiped out nearly 60 percent of Europe — is now a readily treatable bacterial disease spread primarily by fleas transmitting it from infected rodents.

It's not transferable between humans — unless someone sickened with the disease also has a lung infection and is coughing. 

It's also rare. Since 1970, the state has reported 42 human cases, nine of which were fatal.

"The risk of getting plague in California is very low," Vicki Kramer, chief of the state health department's vector-borne disease section, told KPCC. "But despite that low risk, we still recommend that people take precautions to avoid rodents and their fleas."

Those precautions include:

Early symptoms of plague include high fever, chills, nausea, weakness and swollen lymph nodes in the neck, armpit or groin. While treatable in its early stages, the disease can be fatal if left untreated.

Still concerned? The state health department has put together some handy information on the plague in California, along with an interactive map of sites where state health officials have found cases in rodents around California campgrounds going back to 1984: