Rangers Issue Plague Alert

The U.S. Forest Service has closed three popular picnic sites in Angeles National Forest above Tujunga for the long Fourth of July weekend because of a heightened danger of bubonic plague in the area, officials said Friday.

During routine checks in the Big Tujunga Canyon area by Los Angeles County health department officers, several ground squirrels tested positive for sylvatic plague, which in humans is bubonic plague, said Frank Hall, director of the department’s vector management program.

The plague, which can be passed from animals to humans via flea bites, can be deadly in some cases, health officials said. There have been no reported cases of bubonic plague in the county for 12 years, although sylvatic plague was discovered in the area four times last year.

Although health officials said there is no immediate threat to humans, they cautioned people not to handle dead squirrels and to avoid taking pets into areas where there might be a plague danger.

The picnic grounds at Stonyvale, Vogel Flats and Wildwood--often packed during summer holidays and weekends--will remain off limits until at least Tuesday while county health officials and U.S. Forest Service rangers finish killing infected fleas and squirrels, officials said.

Although health officials said sylvatic plague is endemic among ground squirrels in the San Gabriel Mountains, the discovery of the six infected animals in public areas this spring is cause for concern because the plague is more often found in remote, inaccessible areas.

“There are thousands of people who come out because they are nice spots and are near the water,” said Dianne Cahir, a spokeswoman for Angeles National Forest. “Usually, we have to close them down on the Fourth of July because of overcrowding.”

Bubonic plague, once called the Black Death, is believed to be responsible for killing one-quarter to one-third of the population of Europe in the late 14th century. With modern antibiotics, the plague is much less likely to result in death, said Robyn Spano, an environmental health specialist with the county.

The last reported case of a human catching the plague in Los Angeles County was in 1984, when three people were infected. All three survived after receiving antibiotics, health officials said.

Symptoms of the bubonic plague include enlargement of lymph glands near the flea bite and rapid onset of fever and chills. Untreated, the plague can progress to infection of the blood, and sometimes to the more virulent pneumonic plague.

Vector program director Hall said the discovery of the six infected squirrels--three at Wildwood, two at Stonyvale and one at Vogel Flats--was the first confirmation of sylvatic plague in the county this year.

Although the squirrels were trapped May 14, the picnic areas were not closed until Wednesday because local officials waited for the U.S. Centers for Disease Control and Prevention to confirm the results, said Patrick Kaulback, a county environmental health specialist.

County health officials attributed the outbreak of sylvatic plague to increased rainfall this winter, which allowed more grass to grow and created an environment in which squirrels and fleas can thrive.

Spano said workers are spreading a poisonous dust to kill the fleas. Later, the U.S. Forest Service will eradicate a portion of the squirrel population to reduce their numbers.

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Plague Threat

Three areas in the Tujunga District of the Angeles National Forest have been closed after the latest discovery of sylvatic plague in ground squirrels. The Stonyvale, Vogel Flats and Wildwood day-use areas will be closed until Tuesday.

PLAGUE FACTS

During regular monitoring of ground squirrels, the county health department discovered positive blood samples for sylvatic plague.

* About plague: Sylvatic plague is found in animals, such as rodents. In humans, it takes the form of bubonic or pneumonic plague. There has not been a human case of bubonic plague in the county since 1984.

* How it’s transmitted: The bacterium yersinia pestis circulates among rodents via fleas. A human bitten by an infected flea may contract bubonic plague, form of the disease characterized by buboes, or swollen lymph glands. Pneumonic plague affects the lungs and is spread through sneezing.

* Symptoms: Flu-like symptoms begin a few days after infection--headache, fever and swollen lymph glands, usually in the groin.

* Treatment: Antibiotics

* Prevention: Since dogs and cats may pick up infected fleas, try to leave pets at home when visiting the Angeles National Forest. Never feed or play with squirrels or touch a dead squirrel.

* Getting help: If you suspect that you or your pet has been bitten by an infected flea, call the L.A. County Health Services’ Acute Communicable Disease unit at (213) 240-7941.

Sources: L.A. County Department of Health Services; Angeles National Forest; American Meidcal Assn. Encyclopedia of Medicine.