DEER TICKS TURN DEADLY

By Christine Gorman

No bigger than a freckle, the tiny deer tick has sown panic from Montauk to Minneapolis as a carrier of Lyme disease -- an illness that has struck more than 71,000 Americans and left hundreds permanently disabled. Now the minuscule pest is causing even greater alarm. Scientists say deer ticks harbor yet another pathogen, which, unlike the one responsible for Lyme disease, can-in rare cases-actually kill a person in a matter of days.

How worried should Americans be? Plenty, suggests David Quinn, 41, who lives in Briarcliff Manor, New York. An avid jogger, Quinn was stretching in his backyard when he spotted a little black dot on his leg. Once he realized that it was a tick, he quickly removed it with a pair of tweezers. But not quickly enough. Four days later, Quinn fell violently ill. "I had a fever of 102 degrees, and it felt like a hammer was banging in my head," he recalls. "I couldn't keep my head up, but I couldn't lie down either because my back was killing me."

Convinced that he had Lyme disease, Quinn dragged himself to the Westchester County Medical Center. After examining him, however, doctors concluded that Quinn didn't have Lyme disease at all. Instead he had contracted human granulocytic Ehrlichiosis, or HGE -- a newly discovered tick-borne disease that has stricken at least 90 people in New York, Minnesota, Wisconsin and a few other states since 1990, resulting in four deaths. The infection is caused by the Ehrlichia bacterium, a distant cousin of the microbe responsible for Rocky Mountain spotted fever. Fortunately, Quinn had gone to specialists who recognized the infection and cured him with the antibiotic doxycycline. "I had no idea it could be fatal," he says. "Looking back, I'm glad I didn't know the severity of it."

In the past two months, nearly a dozen cases of HGE have been reported in the tick-infested suburbs north of New York City and eight in Wisconsin and Minnesota. Most victims recover completely when given doxycycline. Of the four who died, two were already seriously ill. And one, a 44-year-old man, didn't get the right treatment in time. Researchers fear that many more cases will turn up. "This disease could be as big as Lyme disease," says Dr. Darland Fish, an epidemiologist at Yale who in 1994 helped isolate the bacterium that causes hge. "I expect we'll see hundreds, if not thousands, of cases in the Northeast."

What especially worries those familiar with the newfound ailment is that doctors may fail to recognize it and so may not treat it properly. Unlike Lyme disease, which usually begins with a bull's-eye rash around the site of the tick bite, HGE has no telltale warning signs. Nor is there a definitive test for the disease. Doctors must base their diagnosis on such circumstantial evidence as abnormal spots on white blood cells and a low level of white cells or platelets in the blood. Furthermore, the drug most commonly used for Lyme disease -- amoxicillin -- is useless against the Ehrlichia bacteria.

Scientists, who once believed that Ehrlichia attacked only dogs and horses, now know that at least two species of Ehrlichia can infect humans. One causes HGE, and the other causes a disease called monocytic Ehrlichiosis, a flulike illness first identified in the western hemisphere nine years ago. HGE is spread by the deer tick in Northern states, while monocytic Ehrlichiosis is a mostly Southern syndrome that travels in the Lone Star tick. The disease is found in 30 states, including Texas and Oklahoma. More than 400 cases of monocytic Ehrlichiosis, nine of them fatal, have been documented since the mid-'80s. Unfortunately the two species of Ehrlichia are sufficiently distinct from each other so that the existing test for the monocytic disease will not always betray the presence of the granulocytic one.

Progress toward developing a diagnostic test for the HGE bacterium has been slow. One of the companies that funded some of the key research has filed for bankruptcy. So far, only the Centers for Disease Control and Prevention in Atlanta and one other research lab have access to the bacterial samples. Experts cannot predict when an accurate diagnostic test will be available.

Those who worry whether they can ever again risk a hike through the woods or even enjoy a backyard barbecue may find some comfort in the fact that both types of Ehrlichiosis are easily cured by doxycycline. And since doxycycline works against Lyme disease as well, doctors can, when in doubt, cover all contingencies by using this drug for patients who have been bitten by a tick. A downside of doxycycline: it makes the skin overly sensitive to sunlight and is not normally recommended for pregnant women and young children. The old Lyme-disease precautions now carry an added imperative: when walking in the woods, wear long pants, tuck your pants legs inside your socks and don't stint on the bug sprays

--Reported by Barbara Rudolph/New York

With reporting by BARBARA RUDOLPH/NEW YORK