Eastern Equine Encephalitis (EEE)

How common is EEE in Boston?

In Massachusetts, infected mosquitos are most often found in and around freshwater swamps. EEE infected fewer than 100 people since identifying the virus in Massachusetts in 1938. Mosquitoes that carry EEE are rare in Boston but are much more common in areas such as Plymouth and Norfolk counties. EEE is a very rare disease.

How is the Boston Public Health Commission (BPHC) tracking and controlling EEE?

BPHC works with the Suffolk County Mosquito Control Project to trap and test mosquitoes around Boston for EEE. Trapping and testing happens during the summer and fall months. Mosquito control measures are also implemented during summer and fall months. The city treats wetlands, storm drains, and other areas to limit the number of mosquitoes. Click here for more information.

What are the signs and symptoms of EEE?

Some people infected with EEE do not become ill. When symptoms occur they range from flu-like symptoms such as a high fever and headache, to more serious illness. Other symptoms include muscle aches, lack of energy, neck stiffness, and confusion. Severe cases develop swelling of the brain (encephalitis) which can be dangerous. These symptoms show up four to ten days after a bite from an infected mosquito. Illness usually lasts about 1 to 2 weeks, but it often takes much longer to recover.

How can I help protect myself from mosquitoes?

• Use a mosquito repellent. Repellents approved by the EPA include those containing DEET, oil of lemon eucalyptus, Picaridin or IR3535. Follow the directions on the product label. After returning indoors, wash repellent off with soap and water and wash treated clothes before wearing again. Do not use these products on pets unless the label approves
• If you use a product containing DEET, do not use concentrations of more than 30% on adults and use low concentrations of DEET on children. Apply DEET to exposed skin (not eyes or mouth) and on clothes, but do not use on open cuts or wounds. Do not apply underneath clothes
• Do not let children apply repellants to themselves. Apply the repellant to your hands and rub it on your child. Do not apply repellants to children’s eye, mouth, or hands and use cautiously around ears. Do not apply DEET on infants. Instead use mosquito netting over infant carriers or oil of lemon eucalyptus on children under 3 years of age
• Wear protective clothing such as long sleeved shirts, long pants and socks whenever possible. Tuck your shirt into your pants to keep mosquitoes from going under your clothes
• Although mosquitoes can bite at any time of day, try to limit time outdoors between dusk to dawn when mosquitoes are most active
• Make sure window and door screens don’t have holes in them. Screens in good condition will help prevent mosquitoes from getting inside your house