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URI entomologist predicts deer ticks will be abundant in 2004

Media Contact: Todd McLeish, 401-874-7892

KINGSTON, R.I. -- May 19, 2004 -- During the past 11 years, the abundance of Lyme-disease carrying deer ticks in Rhode Island alternated between high and low levels from one year to the next. Based on this pattern, and since tick numbers were quite low last year, a University of Rhode Island entomologist said that the ticks are expected to be especially abundant in 2004.

Thomas Mather, professor of entomology and director of URI's Center for Vector-Borne Disease, who has been monitoring deer tick populations in the state since 1992, said that the alternating year pattern has proven to be a reliable predictor of tick abundance.

Weather patterns also help Mather predict tick abundance, with wet years usually signaling high tick levels, but last year's wet weather and low tick numbers raised a new question in his mind.

"In 10 of the last 11 years, tick abundance followed the wet weather, but last year it didn't," he said. "I still believe that one piece of the puzzle is clearly weather-related. But there may also be other underlying biological phenomena going on as well."

Regardless of why tick populations ebb and flow, Mather said Rhode Islanders should be especially vigilant against ticks this year. The Centers for Disease Control and Prevention have established a national goal of reducing the rate of Lyme disease to 9.7 cases per 100,000 people by the year 2010. In Rhode Island the current rate is between 30 and 60 cases per 100,000 people.

Mather recommends that all Rhode Islanders take precautions to prevent contracting Lyme disease and implement tick control strategies around the yard. He recommends:

> checking oneself thoroughly every day for ticks;
> applying a repellent containing Permethrin on clothing whenever going outdoors;
> keeping the edge of the yard clear of leaf litter because thatís where ticks are most prevalent; and
> hiring a trained professional pest controller or arborist to apply an appropriate tick treatment throughout the yard.

Adult deer ticks must be attached for 48 hours to transmit the Lyme disease pathogen, while nymphs, which are tiny and difficult to see, need only be attached for 24 hours to transmit the infection.

In addition to Lyme disease, deer ticks also carry a malaria-like protozoan that causes babesiosis and a bacterium that causes human granulocytic ehrlichiosis (HGE). Like Lyme disease, these infections cause flu-like symptoms and are difficult to diagnose, but unlike Lyme disease, they can be fatal.

"Babesiosis is only found in areas where ticks are hyper-abundant, and for now, at least in Rhode Island, that still means it is limited to South County," Mather said. "And the rate of HGE infection in ticks is still quite low in Rhode Island, making it somewhat less of a concern."

For Further Information: Thomas Mather 874-5616