Squirrels Test Positive for Plague

County officials are reminding people to protect themselves when they hike and camp after two squirrels trapped in routine monitoring in the Palomar Mountain area tested positive for plague.

County officials said the two squirrels were trapped last week in the Doane Valley Campground area and that people can protect themselves and pets by remembering some simple rules.

“People need to remember not to feed or play with squirrels when you come across them outdoors,” said San Diego County Environmental Health Director Liz Pozzebon. “Don’t play near squirrel burrows or set up your tents around them, and report dead squirrels to camp rangers.”

Environmental Health Vector Control crews have posted warning signs and dusted squirrel burrows in the area to kill the fleas that can transmit plague from squirrels and rodents to people.

It is not uncommon to find the bacteria — Yersinia pestis — that causes plague in San Diego County’s higher elevations, County officials said. The disease mainly affects wild rodents. However, it can be spread to humans when fleas first feed on infected animals and then bite people, or when people such as hunters handle the tissue or body fluids of infected animals.

People who contract plague can become seriously ill, and even die, unless they are treated quickly with antibiotics. Symptoms include sudden onset of fever, chills and tender lymph nodes.

County officials said hikers and campers in rural mountain areas should look for plague warning signs and always follow simple steps to make sure they don’t come into contact with disease-carrying fleas:

  • Avoid contact with ground squirrels, chipmunks and other wild animals.
  • Do not feed, touch or handle wild animals. Do not rest, camp or sleep near animal burrows in the ground.
  • Do not touch sick or dead animals.
  • Protect your pets by keeping them on a leash, by using flea controls, or even better, by leaving them safe at home.
  • Contact your doctor immediately if you become sick within a week of visiting an area known to have plague.

For more information about plague surveillance, call the County Vector Control Program at (858) 694-2888 or visit the Vector Control Program website



Gig Conaughton is a communications specialist with the County of San Diego Communications Office. Contact