GLOCESTER, R.I. (WPRI) — The R.I. Department of Environmental Management (DEM) is urging everyone to be vigilant after a donkey in Glocester tested presumptive positive for eastern equine encephalitis (EEE).

This is the state’s first mammalian EEE case this year, and the DEM has raised the state’s risk level to high as a result.

The DEM said two mosquito samples from Glocester collected last week tested positive for the virus. The week prior, one mosquito sample from the town tested positive for EEE as well.

No human cases have been reported so far this year. The DEM expects to receive the donkey’s official lab results by the end of the week.

EEE can only be contracted through a bite from an infected mosquito. Though extremely rare in humans, EEE is considered one of the most serious mosquito-borne illnesses that can cause neurological issues if left untreated.

EEE isn’t the only mosquito-borne illness Rhode Islanders should be wary of. West Nile virus has been detected six times in the Ocean State so far this year, of which three were reported in mosquito samples collected in Westerly.

The DEM said the risk for mosquito-borne illnesses typically lasts until the first hard frost, which is meteorologically defined as three straight hours with temperatures below 32 degrees.

In neighboring Massachusetts, five mosquito samples have tested positive for EEE and 99 have tested positive for West Nile virus. The Bay State has also reported two human cases of West Nile virus.

In Connecticut, EEE was detected in only one mosquito sample. However, 105 mosquito samples have tested positive for West Nile virus, and one person has contracted the disease.

Locations are not exact and are meant to illustrate findings by community. Last updated: 9/7/2023. Source: RI DEM, MA DPH, CT CAES

Rhode Islanders should take the following steps to prevent mosquito bites:

Protect yourself

  • Put screens on windows and doors. Fix screens that are loose or have holes.
  • At sunrise and sundown (when mosquitoes that carry EEE are most active), consider rescheduling outdoor activities that occur during evening or early morning. If you must be outside, wear long-sleeved shirts and long pants and use bug spray.
  • Use EPA-approved bug spray with one of the following active ingredients: DEET (20-30% strength), picaridin, IR3535 and oil of lemon eucalyptus or paramenthane. Always read the label and follow all directions and precautions.
  • Do not use bug spray with DEET on infants under two months of age. Check the product label to find the concentration of DEET in a product. The American Academy of Pediatrics recommends that repellents should contain no more than 30% DEET when used on children. Children should be careful not to rub their eyes after bug spray has been applied on their skin. Wash children’s’ hands with soap and water to remove any bug spray when they return indoors.
  • Put mosquito netting over playpens and baby carriages.

Remove mosquito breeding grounds

  • Remove items around your house and yard that collect water. Just one cup of water can produce hundreds of mosquitoes; an unused tire containing water can produce thousands of mosquitoes.
  • Clean your gutters and downspouts so that they can drain properly.
  • 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.
  • Remove or treat any shallow water that can accumulate on top of a pool cover. Larvicide treatments, such as Mosquito Dunks can be applied to kill immature mosquitoes. This environmentally friendly product is available at many hardware and garden stores and online.
  • Clean and change water in birdbaths at least once a week.

Best practices for horse owners

Horses are particularly susceptible to West Nile virus 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 repellents frequently.
  • Monitor animals for symptoms of fever and/or neurological signs (such as stumbling, moodiness, 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.