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DEM, HEALTH Report EEE and West Nile Virus Findings in Mosquitoes Trapped in Great Swamp in West Kingston

PROVIDENCE - The Department of Environmental Management (DEM) and the Rhode Island Department of Health (HEALTH) announce that test results from two mosquito pools, or samples, from a trap set in the Great Swamp in West Kingston have been confirmed positive for Eastern Equine Encephalitis (EEE) and West Nile Virus (WNV).

It is the first time this year that EEE has been positively identified in Rhode Island, although it is presumed likely to be present in other areas of the state. The positive EEE result was found in a pool of 37 mosquitoes trapped on August 26 and was of the Culex species that bites both birds and mammals.

In addition to the EEE finding, WNV was found in a pool of 50 mosquitoes also trapped on August 26 in Great Swamp and was of the Culiseta species that feeds almost exclusively on birds.

As a result, DEM will be setting extra mosquito traps in the South County area for increased assessment.

A third mosquito pool, which was from a trap set in Chapman Swamp in Westerly, has been confirmed positive for Highlands J Virus. The positive Highlands J result was from a species of mosquitoes 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.

These findings are not unexpected at this time of the year. Test results on the remaining 147 mosquito pools from 33 traps set statewide during the week of August 26 are pending at the RI Department of Health (HEALTH) laboratory.

This year, to date in Rhode Island, four pools of mosquitoes have tested positive for West Nile Virus and one pool of mosquitoes has tested positive for EEE. There have been no reported 2013 cases of WNV or EEE in humans in Rhode Island at this time.

Throughout the mosquito season, which typically lasts through the first hard frost, residents are encouraged to protect themselves by eliminating mosquito breeding grounds and avoiding mosquito bites. Personal protection is the first line of defense against mosquitoes that can carry diseases such as WNV and EEE and is by far the most effective way of avoiding infection.

To help protect themselves and their families from mosquito-borne illness, DEM and Health strongly recommend that Rhode Islanders should: • Dress for protection. Wear long pants, long-sleeve shirts and socks during outdoor evening and early morning activities. • Use bug spray. Use mosquito repellent with no more than 30 percent DEET during outdoor activities, particularly at dawn, dusk, and evening hours, when mosquitoes are most active. Do not use repellent on infants. Instead, put mosquito netting over playpens and baby carriages. • Time activities for maximum protection. If possible, minimize outdoor activities between dusk and dawn. • Evaluate the environment. Be sure all open windows are screened, repair any holes in screens, and fix loose screens. Residents and facility groundskeepers should immediately look for and empty standing water following heavy rain, and ensure rain gutters are clear of debris that might trap water. Remove any standing water around yards and houses by emptying planters, wading pools, trash and recycling bins, and other places where water might accumulate to reduce mosquito breeding. Mosquitoes breed in standing water. Just one cup of standing water can produce hundreds of mosquitoes.

Because horses are susceptible to West Nile Virus and EEE, Rhode Island horse owners are reminded that safe and effective vaccines are available to protect their horses. Horse owners should check with their veterinarian to ensure that their horses are properly immunized.

Mosquitoes are trapped every week statewide by DEM staff and tested at the RI Department of Health (HEALTH) laboratory. DEM will normally report mosquito test results once a week on a routine basis, with additional reports as necessary. Test results from mosquitoes trapped this week will be included in next week's announcement. Positive mosquito test results will generally trigger additional trapping to assess risk.

For online information about mosquito-borne diseases, go to DEM's website,, and click on "Public Health Updates," or go to the HEALTH website,, and click on "E" (Eastern Equine Encephalitis), "M" (Mosquitoes), or "W" (West Nile Virus) under "Topics & Programs."

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