Increase in tick disease- fear snowy winter made conditions right for more pests
June 23, 1996|By Frank D. Roylance | Frank D. Roylance,SUN STAFF
As if this year's snowy winter and wet spring haven't caused enough misery, scientists are now concerned that the weather may mean a surge in tick populations, and in the incidence of tick-borne Lyme disease.
"That does seem to be a possibility," said Dr. Dewey M. Caron, a professor of entomology and applied ecology at the University of Delaware.
Two years ago, heavy snow and a cool, wet spring in the Northeast were followed by a jump in tick populations and a 58 percent increase in the number of reported cases of Lyme disease.
Last year, there was little snow and a dry spring, followed by a drop in reported cases of Lyme disease.
This year, Caron said, "conditions have been fairly favorable" for ticks, and their numbers do seem to be up. And "the greater the exposure, the more people that end up with ticks on them, and the more probability of disease."
Lyme disease is caused by corkscrew-shaped bacteria transmitted from wild mice to humans by the bite of the tiny deer tick. It usually produces a distinctive bull's eye-shaped rash and flulike symptoms. Without prompt treatment with antibiotics, it can affect the heart and cause lifelong joint pain.
First identified in Lyme, Conn., in 1976, the disease is now found in 43 states but is most common in eight -- Connecticut, Rhode Island, New York, New Jersey, Pennsylvania, Maryland, Wisconsin and Minnesota. More than 13,000 cases were
reported nationwide in 1994, a record. In 1995 there were 11,600 cases.
Maryland counted 343 cases in 1994, also a record, and up nearly 66 percent from the prior year. Last year, 336 cases were reported.
Deer ticks also have been found to transmit human granulocytic ehrlichiosis or HGE, which causes severe headaches, chills, mental confusion and high fevers. It can be fatal if untreated, but it remains rare. Only a handful of cases have occurred in Maryland.
There is no proof that tick numbers are up this year in Maryland, because there have been no counts. But there is a growing perception that they are.
Caron said inquiries to his University of Delaware office, from Delaware, Maryland and Pennsylvania residents who have found ticks on themselves or in their yards, seem to be up.
Maryland agriculture officials reported last month that the number of people sending ticks in for identification was up 30 percent over last year. But that might reflect only a growing public awareness of Lyme disease.