PALOMAR MOUNTAIN -- Blood samples collected from two ground squirrels at the Doane Valley Campground have recently tested positive for plague, San Diego County vector control officials said Tuesday.

"We found plague in the same park at this time last year. Campers should avoid contact with squirrels and their fleas," said Gary Erbeck, director of the Department of Environmental Health.

"Do not put your tents near squirrel burrows, do not feed the squirrels and warn your children not to play with the squirrels," he said.

Fleas can spread the plague to humans, but that has never happened in San Diego County, officials said.

Plague warning signs are posted in all areas where plague has been confirmed. Educational pamphlets are also available at the ranger's station.

For more information about plague surveillance, call county vector control at (858) 694-2888 or go to www.SDVector.com.