Tuolumne Meadows Campground in Yosemite National Park has closed after two squirrels living in the park were found to be carrying bacteria that causes plague, officials said.
The risk was low to humans, but officials wanted to exercise caution, said Vicki Kramer of the California Department of Public Health.
"Getting a bite by an infected flea is the primary way that people get plague," said Kramer. A small amount of insecticide dust was put into burrows where rodents live to reduce the chances of human infection, said Kramer.
Plague activity is found in the park every year, but the last case of human plague in Yosemite was in 1959. Kramer said this year has seen higher evidence of plague in rodents and fleas than past years.
Last week, Crane Flat Campground was closed for treatment after a child from Los Angeles County was infected. The child was hospitalized and recovering, said James Watt, chief of the division of communicable disease control with the California Department of Public Health.
Many regions of California have a history with plague activity, especially in higher elevations, said Kramer. However, Watts said the chances of humans catching plague today is very low, because plague exists "really only ... in wildlife settings in the mountain areas."
Tuolumne Meadows is scheduled to open Friday afternoon. Officials will be making an assessment before opening again to make sure the treatment was effective, said Kramer.
" The message to campers at Yosemite and all of our wilderness areas is to stay away from rodents and their burrows," Kramer said. "Don't feed the cute chipmunks and squirrels. They do potentially carry infected fleas."
Kramer recommends campers wear repellent on their pant legs or socks.