Agoura Hills Squirrel Tests Positive for Plague Bacteria

The season for rodent-carried plague has begun, with the dangerous disease detected for the first time this year in a ground squirrel trapped in Agoura Hills, county health officials said Wednesday.

Residents of the area--the squirrel was trapped in a vacant lot on Triunfo Canyon Road--should spread insecticides to control fleas, which can transmit the disease to humans or pets, and either eliminate or avoid squirrels on their property, said Frank Hall, director of insect-borne disease control for the county Department of Health Services.

Visitors to parks or campgrounds in areas where the health department has posted plague warnings should avoid squirrels and rid pets of fleas when they go home, Hall said.

The bacteria that cause plague often live in the blood of burrowing rodents, which remain healthy, Hall said. Occasionally, the bacteria kill their hosts. It is during such a die-off that plague can become a threat to humans. When an infected squirrel dies, fleas leave the dead rodent in search of a new host.

The plague bacteria last infected a human in Los Angeles County in 1984, in a non-fatal case in Diamond Bar. If such an infection is not promptly treated with antibiotics, it can prove deadly within two days.

The infected animal from Agoura Hills was trapped in April, but tests confirming the presence of the plague bacteria were completed just last week, Hall said. Warning signs were posted in April at the spot where the rodent was trapped, but a public announcement was withheld until the test results were known, he said.