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DEM, RI DOH Report Fourth West Nile Virus Finding

Public Reminded to Protect Themselves against Mosquito Bites

PROVIDENCE - The Department of Environmental Management (DEM) and the Rhode Island Department of Health (RI DOH) announce that a sample of mosquitoes collected on September 21 in West Kingston has tested positive for West Nile Virus (WNV). This is the fourth finding of WNV in Rhode Island this year.

The positive finding is not unexpected. West Nile Virus is increasingly being detected in mosquito samples trapped in neighboring states. Mosquito-borne diseases are more prevalent in late summer and early fall, and risk typically lasts until the first frost. Samples are tested weekly at the Rhode Island State Health Laboratories. The positive mosquito pool is a species that can bite both birds and humans.

Throughout the mosquito season, the public is reminded to:

Dress for protection. Wear long pants, long-sleeve shirts and socks during outdoor evening activities.

Use bug spray. Use mosquito and tick repellent with no more than 30 percent DEET during outdoor activities, particularly at dusk and during evening hours, when mosquitoes are most active. Do not use repellent on infants.

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. 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.

There have been no reports of human cases of WNV in Rhode Island this year. However, there have been five human cases of WNV in Massachusetts. On September 29, the Massachusetts Department of Public Health announced the first WNV-related fatality of the year in Massachusetts.

There have been no reports of Eastern Equine Encephalitis (EEE), another mosquito-borne illness, in Rhode Island, Massachusetts, or Connecticut this season.

Late summer and early fall are also considered high-risk seasons for the transmission of both WNV and EEE to horses by infected mosquitoes. Rhode Island State Veterinarian Scott Marshall, DVM has issued several recommendations to horse owners to help protect their animals from getting bitten by mosquitoes. He advises horse owners to use repellents on their animals; consider stabling their horses indoors at dawn and dusk, which are considered heavy mosquito feeding times; remove free standing water from stable areas; and consult with their veterinarian to determine whether their horses are properly immunized, as vaccination is safe and effective in the prevention of EEE in horses. A vaccination for horses is also available for WNV.

Mosquitoes are trapped weekly statewide by DEM and tested at the Rhode Island State Health Laboratories. DEM announces mosquito test results once a week from late June through September, with additional reports as necessary. Test results from the remaining 83 pools of mosquitoes trapped on September 21 will be included in next week's announcement.

Visit for additional prevention tips and for Rhode Island-specific data.

Related links

  • Department or agency: Department of Environmental Management
  • Online:
  • Release date: 10-01-2015

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