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Final Weekly Mosquito Advisory

PROVIDENCE The Rhode Island Department of Environmental Management (DEM) and the Rhode Island Department of Health (RIDOH) today announced test results for their final set of mosquito samples this season. Seventy-eight mosquito samples from 30 traps set on Monday, September 25 have tested negative for both West Nile Virus (WNV) and Eastern Equine Encephalitis (EEE). Also, 51 mosquito samples from 30 traps set on Monday, September 18 and 95 mosquito pools from 30 traps set on Monday, September 11 have been confirmed negative for WNV and EEE. Testing is being suspended in light of the cooler temperatures and the related drop in mosquito populations statewide.

While mosquito numbers are lower, Rhode Island has not yet experienced a hard frost which eliminates the risk of contracting mosquito-borne diseases. Last month, RIDOH confirmed the state's first human case of WNV in 2017. The 66-year-old from Providence County began to experience symptoms of WNV on September 15, 2017. People may still see an occasional mosquito, particularly on warmer days and nights, and should continue to protect themselves against bites. The public is encouraged to avoid mosquito bites by taking the following steps: Remove anything around your house and yard that collects water; just one cup of water can produce hundreds of mosquitoes. Clean gutters and downspouts to ensure proper drainage, and repair holes in window screens. Remove any water from unused swimming pools, wading pools, boats, planters, trash and recycling bins, tires, and anything else that collects water, and cover them. Change the water in birdbaths at least two times a week, and rinse out birdbaths once a week. Use EPA-approved bug spray with one of the following active ingredients: DEET (20-30% strength), picaridin, IR3535, and oil of lemon eucalyptus or para-menthane-diol. Do not use bug spray on infants under 1 year of age. Minimize outdoor activity at dawn and at dusk when mosquitoes are most active. Put insect netting over strollers and playpens. Wear long sleeves and long pants whenever possible, particularly if you are outdoors during dawn and dusk. The public is also reminded to use screens on windows and doors and to repair holes in screens in order to keep mosquitoes out of their home. During the mosquito season, there were three confirmed local findings of WNV and three confirmed findings of EEE in mosquito samples. There was one confirmed human case of WNV in Rhode Island, and no confirmed cases of EEE. Mosquitoes were trapped weekly by DEM from June through September and tested at the State Health Laboratories at the RIDOH.

Visit or additional mosquito prevention tips and for local data. For more information about DEM divisions and programs, visit Follow us on Twitter (@RhodeIslandDEM) and/or Facebook at for timely updates.

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  • Department or agency: Department of Environmental Management
  • Online:
  • Release date: 10-06-2017

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