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Last Updated

01 Jul 2003

Source: Wall Street Journal, July 1, 2003


Serious Diseases Cloud Summer

Monkeypox, SARS, Lyme and West Nile Are Viewed as Potential U.S. Threats


Once upon a time, summer would bring, at worst, a sunburn and bee stings. This year, scientists say those could be the least of our problems.

Monkeypox, a virus native to rain forests in Africa, broke out in May in the Midwest. Health officials are worried about a comeback of SARS. Meanwhile, they are gearing up for an expected resurgence of West Nile virus, which killed 284 patients last year and has already infected animals in 28 states. Lyme disease, too, remains a threat. Fever and muscle aches can no longer be casually dismissed as a case of the flu.

Of course, severe acute respiratory syndrome and monkeypox are rare: only eight people in the whole country have been confirmed to have had SARS, and only those in contact with prairie dogs have gotten monkeypox.

West Nile is of greater concern to health officials. After first appearing in the U.S. in a single state, New York, in 1999, the virus by the end of last summer had spread to 44 states, infecting 4,156 people, according to the U.S. Centers for Disease Control and Prevention in Atlanta. Spread by mosquitoes, the disease before 1999 had been seen only in Africa and the Middle East.

No human cases have been reported yet this summer, but in recent years most have appeared in the later part of the summer. "We remain very vigilant," says Julie Gerberding, the CDC's director, whose own husband developed a fever and flu-like symptoms last summer after being bitten by West Nile-infected mosquitoes in the backyard.

James Hughes, the CDC's top infectious-diseases official, predicts the disease will reach the entire country this year. He is particularly concerned about California, which reported just one case last year. The warm climate there, plus the dense population, sets the stage for a mosquito field day.

Not everyone who is infected with West Nile virus gets sick. About 20% develop fever, body aches, and sometimes skin rash and swollen lymph glands. Like the flu, it passes in a few days. In fact, West Nile feels so much like the flu that some people don't recognize what it is or call their doctor, physicians say.

But about one in 150 people develops encephalitis or meningitis, potentially fatal conditions that cause inflammation of the brain or spinal cord.

Michael Fleming, a family physician in Shreveport, La., which was hard hit last year by West Nile, says when patients call in with flu-like symptoms in the summer, "we try to get them in as quickly as possible." He says he looks for signs of encephalitis, such as severe headache. In his practice, two cases of the virus were diagnosed last summer, he says. Neither patient died.

Concerns also persist about Lyme disease, a bacterial infection spread by deer ticks, which penetrate human skin and inject the bacteria into the blood. Most of the approximately 18,000 cases last year were reported in a few regions: the Northeast, the mid-Atlantic region, and Wisconsin and Minnesota. While some people have developed serious symptoms, such as meningitis, most cases are treatable with antibiotics, says Paul Mead, a Lyme disease expert with the CDC. Removing a tick even up to 48 hours after it has embedded itself in skin greatly reduces the risk of getting the disease, Dr. Mead says, because it takes time for the tick to produce and then transfer the disease.

Why are more diseases seemingly popping up out of nowhere? Improved methods of detection is a big reason, says Dr. Hughes, director of the CDC's National Center for Infectious Diseases. "We're finding more of these things now because we have modern laboratory procedures ... and a higher index of suspicion," he says. With so much travel between countries now, "there seems to be no end to it," he adds.

"West Nile was just the first shot across the bow," warns Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, and an adviser to the U.S. Department of Homeland Security.

He cites Japanese encephalitis, which infects as many as 50,000 people a year throughout Asia and has a mortality rate as high as 60%, as an example of a disease that could easily be carried to the U.S. The disease is also transmitted by mosquitoes and could be spread by the arrival of a single infected mosquito in a cargo shipment from Asia, he says.

To hold West Nile at bay, local mosquito-control agencies around the country are spraying insecticides. The CDC and local health officials are urging people to protect themselves by wearing long shirts and pants outside at night, using mosquito repellent that contains DEET -- a chemical that repels mosquitoes and that the CDC says is safe -- and emptying stagnant water from flower pots and other containers.

Federal officials also say two tests have been developed to screen the blood supply, after 13 people were infected last year with West Nile virus from blood transfusions. The tests will be introduced in clinical trials at several blood banks throughout the country this summer.

Adding to public concerns about all these illnesses is the striking similarity in their symptoms -- symptoms that typically mimic the common cold or flu. Dr. Fleming's office in Louisiana got up to five calls a day from worried patients after the monkeypox outbreak was reported June 7. Most callers were reassured when his staff told them that only those who had had contact with prairie dogs were considered at risk. Three patients came in to be seen anyway, he says; they turned out to have poison ivy.