TIVERTON, R.I. — The Rhode Island Department of Environmental Management (DEM) and the Rhode Island Department of Health (RIDOH) announced on July 14 that mosquito samples collected in Tiverton, Pawtucket and Westerly on June 26 tested positive for Eastern Equine Encephalitis virus (EEE).
These are the first findings of EEE in Rhode Island this year. All the positive mosquito pools are species that bite birds and mammals (including humans).
There are no confirmed human cases of EEE in Rhode Island.
However, because summer and fall are peak seasons for mosquito-borne disease transmission to people, Rhode Islanders should be aware of the symptoms of EEE.
Severe cases of EEE (involving encephalitis, an inflammation of the brain) begin with the sudden onset of headache, high fever, chills, and vomiting. If you think you or a family member may have EEE, it is important to consult your healthcare provider for proper diagnosis.
In addition to EEE, Rhode Island tests mosquitos for West Nile Virus (WNV). To date, there have been no confirmed local findings of WNV in a mosquito sample. There are no confirmed human cases of WNV in Rhode Island.
With WNV and EEE established throughout the state, the public is reminded to eliminate mosquito breeding grounds and avoid bites, where possible. The following precautions are advised:
• 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.
Controlling mosquito populations and promoting personal protection against bites are central to Rhode Island’s action plan for WNV and EEE. In partnership with RIDOH, DEM distributed mosquito larvicide to local communities in late May to treat area catch basins.
Catch basins are prime breeding grounds for mosquitoes in both urban and suburban settings. Horses are particularly susceptible to WNV and EEE. Horse owners are advised to vaccinate their animals early in the season and practice the following:
• Remove or cover areas where standing water can collect.
• Avoid putting animals outside at dawn, dusk or during the night when mosquitoes are most active.
• Insect proof facilities where possible and use approved repellants frequently.
• Monitor animals for symptoms of fever and/or neurological signs (such as stumbling, depression, loss of appetite) and report all suspicious cases to a veterinarian immediately. If you are unsure if your horse is properly vaccinated you should consult with your veterinarian.
• Horses are the most susceptible domestic animal, but other, less common species such as ratites (emus, ostriches, etc.) and camelids (alpacas and llamas) are occasionally infected. Owners of ratites and camelids should consult with their veterinarian regarding vaccination of their particular animals.
Mosquitoes are trapped weekly by DEM and tested at the RIDOH State Health Laboratories. The RIDOH State Health Laboratories have recently changed their testing methodology to use a more sensitive testing method which may account for an increase in positive results going forward.
DEM issues advisories on test results from late June through September, with additional reports as necessary. Test results are pending for the remaining traps set on June 26 and additional traps set on July 5 and July 10, and will be included in future announcements.
Typically positive test results trigger additional trapping to assess risk; the recent findings will result in additional trapping in the Tiverton, Pawtucket and Westerly areas where the positive mosquito samples were found.