Plague No Longer a Scourge But Still a Threat

By DEBORAH BAKER

Aug. 2, 1998 12 AM PT

ASSOCIATED PRESS

SANTA FE, N.M. — Veterinarian Barbara Swanson didn’t think much about it when the sweet, sick cat she was treating for an infection bit her on the thumb.

Four days later, a high fever and intense pain in her arm sent her to the hospital. The diagnosis: bubonic plague.

Esther Morrison thought her 70-year-old husband had overexerted himself when he stopped splitting wood, complained of stomach pain and told her not to count on him for supper.

Two days later, he was dead. The diagnosis: septicemic plague.

Despite its medieval aura--the Black Death wiped out one-quarter of Europe’s population in the Middle Ages--plague has a decidedly modern face. There are still sporadic outbreaks around the world. In the United States, 10 to 15 cases are reported in humans each year, mostly in the West.

That makes it rare--but worrisome nonetheless.

“We treat it very seriously because of the risk of human-to-human spread and the high fatality rate,” said Kenneth Gage, chief of the plague section of the Division of Vector-Borne Infectious Diseases with the Centers for Disease Control and Prevention.

Plague is a bacterial disease of rodents that generally is transmitted through flea bites. The culprits are most likely to be rock squirrels, ground squirrels, prairie dogs or pack rats living roughly in the western half of the United States. Most of the human cases occur in the Southwest--New Mexico accounts for more than half--and along the Sierra Nevada in California. There have been human cases reported in at least 13 Western states.

“The closer you get to the Rocky Mountains and on west, the more plague you’re going to find,” said Gage, whose office is in Fort Collins, Colo.

And it doesn’t require unsanitary conditions or urban squalor. A roaming cat can bring plague to a suburban living room.

Although flea powder and other precautions can reduce the risk, and prompt treatment with antibiotics can cure it, plague kills about 16% of its human victims, according to the CDC.

There were 394 human plague cases in the nation from 1949 through 1997, 63 of them fatal. New Mexico logged 218 of those, including 30 fatalities, said Paul Ettestad, public health veterinarian with the state Department of Health.

“It’s a disease that can be fatal if not recognized and treated early enough,” Ettestad said.

Swanson, the nation’s first human plague case this year, saw a doctor as soon as she felt sick and spent two days in the hospital. Nearly two months later, she still has lingering fatigue.

“I’m working very little because I’m so tired,” said Swanson, 45, whose veterinary clinic is in Pojoaque, just north of Santa Fe. “It’s getting better, but it’s just taking some time.”

Esther Morrison’s husband, Donald, a retired metallurgical engineer, died in August 1984 after being stricken at their house on a wooded hillside a few miles from Santa Fe.

Dead ground squirrels found in the family’s woodpile were later determined to have had plague. But the doctor he saw twice didn’t recognize the disease.

Septicemic plague “is so sneaky,” said Esther Morrison, whose family created a memorial fund after her husband’s death to educate doctors in rural areas about the disease.

Bubonic plague, which accounts for 80% of cases, is marked by swollen lymph glands, called buboes. It’s harder to diagnose septicemic plague, which circulates in the bloodstream, and pneumonic plague, which infects the lungs and is particularly dangerous because it can be transmitted through coughing. Generally, those in contact with a pneumonic plague victim are also treated with antibiotics.

“In the United States, we actually haven’t had person-to-person transmission since the 1920s--not that it couldn’t occur,” said the CDC’s Gage.

Most people become sick two to seven days after infection. Other symptoms are fever, chills, headache, muscle pain, nausea, vomiting and diarrhea.

The incidence of plague appears to be cyclical, apparently linked to the high-moisture, milder winters typical of El Nino years that cause rodents to thrive, Ettestad said. This is a big year, with the rodent population in New Mexico estimated at 10 to 20 times higher than last year--when no one in the state caught plague.

Believed to have evolved in central Asia, plague is new to the United States. It arrived about 1900 in San Francisco aboard trading ships from China and spread from urban rats into the wild rodent population of the West. There were outbreaks in ports along the Gulf of Mexico, but it never got established in the native rodents there, according to the CDC’s Gage.

Cats are more susceptible to plague than dogs, and get sicker. Listlessness and not eating are clues that a cat is ill.

“If you become sick and there’s a sick cat in the house, go see your doctor,” Swanson advised.

Plague also can be contracted by handling infected animals. Hunters, for example, are at risk if they don’t wear gloves while skinning animals.

Esther Morrison gives her cat anti-flea treatment regularly and sprays her woodpiles. She says if she were to get sick and suspected plague, she would be aggressive about demanding the appropriate treatment.

“I’m not afraid of plague anymore because I’ve read so much,” she said. “Knowledge is a weapon. I know that no one has to die.”

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Plague Facts

What it is:

* A bacterial disease of rodents generally transmitted through flea bites.

* May be transmitted by direct contact with infected rodents, wildlife, pets or people.

* Most people become ill two to seven days after infection.

* Symptoms may include fever, chills, swollen lymph nodes in groin, armpit or neck, headache, muscle pain, vomiting, nausea, diarrhea.

* Can be cured by prompt treatment with appropriate antibiotics.

* Can be fatal.

Ways to reduce the risk:

* Avoid sick or dead animals.