City of Portsmouth, Health Department, 1 Junkins Avenue, Portsmouth, NH 03801. Tel: (603) 610-7273

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EEE or Eastern Equine Encephalitis


EEE or Eastern Equine Encephalitis is a rare but very serious disease transmitted by the bite of an infected mosquito. People infected with EEE may experience no symptoms, mild flu-like symptoms accompanied by fever, headache and sore throat, or in severe cases, sudden high fever, severe headache, stiff neck, coma and death. People do not get EEE from each other, only from the bite of a mosquito that carries the virus. One third of the people who become seriously ill will die, others may suffer permanent brain damage. There is no specific treatment for EEE. Mosquitoes carrying EEE have been found in Rockingham County this year. To protect yourself, avoid mosquito bites by taking the following precautions.

Protective measures you can take are:

  • Consider the use of an effective insect repellent, such as one containing DEET. A repellent containing 10% or less DEET (N,N-diethyl-methyl-meta-toluamide) for children, and no more than 30% DEET for adults. Use DEET according to the manufacturer's directions. Adults should apply DEET containing products to children by first applying it to their hands, then wiping it on the child's skin. Repellents with DEET should not be used on infants less than two (2) months old. Repellents that contain Picaridin or oil of lemon eucalyptus have also been determined to be effective, but oil of eucalyptus should not be used on children under the age of three (3) years old. Use repellents sparingly and wash skin and clothing after returning indoors. As with all chemicals, store out of the reach of children.

  • Wear protective clothing when outside, particularly during dawn, evening and nighttime when mosquitoes are most active. Long pants, long-sleeved shirts and socks will help cover skin to prevent biting.

  • Use mosquito netting baby stroller covers. These can be found in children's furniture and accessory stores. Ensure the stroller covers are snuggly in place around the outside of the stroller or carriage so that mosquitoes cannot get under it.

  • Vitamin B, ultrasonic devices, incense, and bug zappers have not been shown to be effective in preventing mosquito bites.
For information on how to protect your home and prevent mosquito breeding areas on your property, contact the Portsmouth Health Department at 610-7273.
Protecting Your Home and Yard from Mosquitoes
When at home, you can take steps to protect yourself from Eastern Equine Encephalitis (EEE), West Nile Virus (WNV) and other potential diseases carried by mosquitoes, by following these prevention guidelines.
  • Mosquitoes can enter homes through unscreened windows or doors, or through torn screens. Make sure that doors and windows have tight-fitting screens. Repair or replace all screens in your home that have tears or holes.

  • Eliminate even small amounts of standing water. Mosquitoes can breed in small amounts of water that have been standing for only a few days.

  • Remove old tires from your property.

  • Dispose of tin cans, plastic containers, ceramic pots, or other containers that can hold water. Don't overlook containers that have become overgrown by aquatic vegetation.

  • Drill holes in the bottom of recycling containers that are left outside. It is important that the holes be in the bottom. Holes low on the sides can still allow mosquito breeding.

  • Make sure roof gutters are clean and draining properly.

  • Clean and chlorinate swimming pools and hot tubs. If not in use, keep empty and covered and keep covers free of standing water.

  • Aerate garden ponds or stock them with fish.

  • Turn over wheelbarrows and change water in birdbaths at least twice weekly.

  • Turn over plastic wading pools when not in use.

  • Remind or help neighbors to eliminate breeding sites on their properties.

  • Weeds, tall grass, and bushes provide an outdoor home for the adult Culex pipiens mosquito (the common northern house mosquito), which is most commonly associated with West Nile virus. Keep your lawn trimmed.
If you have further questions about EEE, WNV, or information provided here, please contact the Portsmouth Health Department at 610-7273, or you may contact the State of New Hampshire Department of Health and Human Services' toll free hotline at 1-866-273-6453 from 8 AM to 4:30 PM Monday through Friday.