Horse in Richmond dies from Eastern Equine Encephalitis

First Reported Case of EEE in a Horse from Rhode Island

PROVIDENCE - The Department of Environmental Management announces that test results from the remaining 123 mosquito pools, or samples, from 35 traps set statewide during the week of September 9 are negative for both West Nile Virus and Eastern Equine Encephalitis. The testing results were confirmed by the RI Department of Health (HEALTH) laboratory.

DEM and HEALTH announced last week that both Eastern Equine Encephalitis (EEE) and West Nile Virus (WNV) were confirmed in samples of mosquitoes collected on September 9 in Rhode Island. Test results from one mosquito pool, or sample, from a trap set in Exeter was confirmed positive for Eastern Equine Encephalitis (EEE), and three mosquito pools from traps set in Providence, East Providence and North Kingstown were confirmed positive for West Nile Virus (WNV).

This year, to date in Rhode Island, seven pools of mosquitoes have tested positive for WNV and four pools of mosquitoes have tested positive for EEE.

Because horses are susceptible to WNV 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. RI State Veterinarian Scott Marshall, DVM has learned that test results on a one year-old horse from Wyoming, RI were confirmed positive for EEE. 

The horse had to be euthanized on September 20 at Tufts Veterinary School in Massachusetts, where it had been brought for treatment. Records indicate that the horse was not fully immunized against EEE. Last week the Connecticut Department of Agriculture confirmed the state's first reported case of EEE in a horse this year. The two-year old miniature horse was from nearby Griswold, Connecticut and had not been vaccinated against EEE or WNV.

WNV is most commonly spread by infected mosquitoes and can cause febrile illness, encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord). Anyone living in an area where WNV is present in mosquitoes can get infected. EEE is one of the most severe mosquito-transmitted diseases in the United States with approximately 33% mortality and significant brain damage in most survivors. Infants and the elderly are at greatest risk for serious complications. There is no specific treatment for EEE; care is based on symptoms.

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. Warm evenings, if and as they occur, will continue to be of concern for mosquito biting activity until the first hard frost. 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.

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, 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".