RIDOH: EEE Human Case Heightens Risk

WEST WARWICK —  On Friday, the Rhode Island Department of Health announced the state’s first human case of Eastern Equine Encephalitis (EEE) in a person over the age of 50 from West Warwick, the first human case in Rhode Island since 2010.

The Centers for Disease Control and Prevention (CDC), which performs the EEE testing, notified RIDOH of the positive result.

This announcement comes a day after the Rhode Island Department of Environmental Management (DEM) issued an announcement about a horse in Westerly that had tested positive for the disease. Over the past few weeks, mosquitoes carrying the disease have been found in Westerly and Central Falls. This is a higher-than-average risk summer for mosquito-borne diseases in southeastern New England. Massachusetts has announced four human cases of EEE and seven cases in horses. Connecticut also has found EEE and West Nile Virus in mosquitoes and two cases in horses.

“In Rhode Island, we have confirmed EEE in both a horse and a human, which indicates that there is a high risk for transmission of disease to humans through mosquito bites,” said Ana Novais, Deputy Director of RIDOH. “EEE is a rare, but very serious disease.  We strongly recommend that people everywhere in Rhode Island protect themselves and their families by using insect repellent, minimizing outdoor exposure at dusk and dawn, and wearing long sleeves and pants when outdoors at those times.  People must also reduce opportunities for mosquitoes to breed by eliminating standing water around their homes.”

Due to the elevated risk, the Department of Environmental Management (DEM) is adding traps to capture and test more mosquitoes statewide. Typically, DEM sets between 25 and 30 traps in Westerly, Charlestown, South Kingstown, North Kingstown, Exeter, Warwick, Cranston, Johnston, Providence, Central Falls, Pawtucket, East Providence, Barrington, Warren, Bristol, Tiverton, Portsmouth, and Newport. DEM will add traps in West Warwick and the northern Rhode Island communities of Burrillville, North Smithfield, Woonsocket, and Cumberland.

This step will allow scientists from DEM and the University of Rhode Island to optimize other response measures, such as the aerial spraying of pesticide, to continually assess mosquito species, volume, and infection and, working with RIDOH, minimize the risk of further human disease.

The state will target eliminating both mosquito larvae — small organisms just hatched from eggs living in freshwater bodies — and adult biting mosquitoes. Larvicide is a targeted approach to killing the larvae before they mature. It often consists of applying a naturally occurring bacteria in solid granule form from a helicopter onto mosquito breeding grounds such as swamps. For example, because of Chapman Swamp’s history as a breeding ground for mosquitoes that carry EEE, the Town of Westerly has applied a larvicide called Bti in the swamp since 1997. It is an environmentally friendly product and does not pose a risk to human health.

The state is taking all necessary preparations for conducting aerial spraying to kill adult biting mosquitoes. RIDOH and DEM are actively evaluating options and will continue to provide updates. The state will release a spraying schedule before any spraying occurs.

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. 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.

Get rid of mosquito breeding grounds

• Get rid of anything around your house and yard that collects 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 asMosquito Dunks can be applied to kill immature mosquitoes. This environmentally-friendly product is available at many hardware and garden stores and on-line.
• Change the water in birdbaths at least two times a week and rinse out birdbaths once a week.

Best practices for horse owners

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 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.

Visit http://www.health.ri.gov/mosquito for additional mosquito prevention tips, videos, and local data. For more information about DEM divisions and programs, visit www.dem.ri.gov. Follow us on Facebook at www.facebook.com/RhodeIslandDEM or on Twitter (@RhodeIslandDEM) for timely updates.