For Release: September 29, 1997

Contact: Alan Gettman, Ph.D. 277-6151

Stephanie Powell 277-2771 ext. 4418

PROVIDENCE - The RI Department of Environmental Management has received test results showing that one pool of 10 exclusively bird-biting mosquitoes collected Monday, September 22 in Westerly tested positive for Eastern Equine Encephalitis.

The Culiseta mosquitoes, which were trapped in the downtown area next to the river on Clark Street, are not human biters.

Test results also showed the presence of Highlands J virus in samples of bird-biting mosquitoes trapped at two Westerly locations - Pound Road in Chapman's Swamp and near the Tourist Center on Route 1 - as well as from one trap near the Town Farm Recreation Area in Tiverton.

"The Highlands J virus," said Alan Gettman, DEM Mosquito Abatement Coordinator, "does not produce disease in humans, nor does it guarantee the presence of EEE. It is used as an indicator of the possibility of EEE and simply indicates that environmental conditions are right for the EEE virus to multiply and that the level of risk may be higher."

Gettman said a number of factors are helping to keep EEE at a minimal level, including a substantially reduced mosquito population because of the dry summer. He noted that EEE risk is relatively low at this time due to dwindling numbers of mosquitoes, reduced mosquito biting activity during cool evenings, and people wearing cool weather clothing.

"However," Gettman said, "people should continue to take normal precautions against mosquitoes until the first hard frost."

The findings are not unexpected, for they are detected almost every year.

Putting it into perspective, Gettman said that Highlands J has been found in 9 of the past 10 years; EEE has been found in bird-biting mosquitoes in 7 of the past 10 years; and EEE has been found in human-biting mosquitoes in 3 of the past 10 years.

The one EEE isolation found in an occasional human-biting mosquito through DEM's mosquito trapping program this year came from a September 2 isolation in Westerly. In addition, a horse from the Bradford area of Westerly, euthanised at Tufts University on September 10, tested positive for Eastern Equine Encephalitis (EEE.) It is believed the horse was bitten by a mosquito carrying the EEE virus in late August or early September.

In response to the September 2 isolation, DEM expanded its surveillance to include residential areas throughout Westerly, including a trap near the reported horse case.

The normal precautions people should continue to take include ensuring screens are in good repair, reducing unnecessary outdoor activity at dawn and dusk; wearing protective clothing such as long pants and long-sleeved shirts; and applying products containing the mosquito repellent DEET to clothing.

Formulations that contain more than 20 percent DEET are unnecessary and may enhance skin reactions on some people. Repellents should not be used on infants, and children should be cautioned to avoid getting repellents in their eyes. Residents should also keep their backyards free of water-holding containers which create areas where mosquitoes can be produced.

The mosquito abatement program has information on a website: www.uri.edu/research/eee There is also a DEM webpage with rabies contacts information.