Wednesday, September 5, 2012

DEM finds more mosquito-borne disease

DEM announces EEE found in mosquitoes trapped in Tiverton
DEM news release

PROVIDENCE - The Department of Environmental Management announces that test results from one mosquito pool, or sample, from a trap set in northern Tiverton has been confirmed positive for Eastern Equine Encephalitis (EEE). It is the third time this year that EEE has been positively identified in Rhode Island. The positive EEE result was from a Culiseta species that feeds almost exclusively on birds.

The positive EEE finding came from mosquitoes trapped by DEM staff on August 20 and tested at the RI Department of Health (HEALTH) laboratory. The results were confirmed today.


In addition, a sample of mosquitoes also collected on August 27 in North Kingstown near Wickford has tested positive for Highlands J virus. The positive result was also from a Culiseta species that bites birds. Highlands J virus is a bird disease that doesn't affect humans, but which is an indicator that environmental conditions are appropriate for the transmission of other mosquito-borne viruses.

According to Alan Gettman, Ph.D., DEM's mosquito abatement coordinator, the positive results were not unexpected and confirm that there are infected mosquitoes in the environment. Therefore, all Rhode Islanders should take extra care to protect themselves, particularly when mosquito-biting activity is high.

Biting activity depends on several conditions. It generally is greatest from dusk to dawn. During the day it decreases in sunny areas at lower temperatures and increases in shady areas at higher temperatures. Biting activity also generally increases with high humidity and with low wind.

Personal protection is the first line of defense against mosquitoes that can carry diseases such as West Nile Virus and EEE and is by far the most effective way of avoiding infection. People should routinely use mosquito repellent and cover up when mosquito-biting activity is greatest. They should place mosquito netting over playpens and carriages outside, and be sure that screens are in good repair. Mosquito repellent should contain no more than 30 percent DEET, and it should not be used on infants.

This year, to date in Rhode Island, three pools of mosquitoes have tested positive for Eastern Equine Encephalitis and three pools have tested positive for West Nile Virus.

Mosquitoes in Rhode Island are trapped every week statewide by DEM staff and tested at the RI Department of Health laboratory. DEM will normally report mosquito test results once a week on a routine basis, with additional reports as necessary. Routine test results from remaining pools of mosquitoes trapped during the weeks of August 20 and August 27 will be included in next week's announcement.

For online information about mosquito-borne diseases, go to DEM's website, www.state.dem.ri.gov, and click on "Public Health Updates", or go to the HEALTH website, www.health.ri.gov, and click on "E" (Eastern Equine Encephalitis) or "W" (West Nile Virus) under "Health Topics".