Protecting Yourself from Mosquitoes
This information is provided by the Massachusetts Department of Public Health (DPH) and the U.S. Centers for Disease Control and Prevention (CDC).
What diseases can mosquitoes spread?
In Massachusetts, some mosquitoes can transmit eastern equine encephalitis (EEE) virus and West Nile virus (WNV).
- Eastern equine encephalitis (EEE) is a rare but serious viral disease. Typical symptoms include high fever, stiff neck, headache, and lack of energy. Inflammation and swelling of the brain, called encephalitis, is the most dangerous result. Most cases in Massachusetts occur in the southeastern part of the state.
- West Nile virus (WNV) was first identified in the United States in 1999. Most WNV infections do not cause any symptoms. Mild WNV infections can cause fever, headache and body aches, often with a skin rash and swollen lymph glands. In a small percentage of people infected by the virus, the disease can be serious, even fatal. More severe infections can cause headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, paralysis, and, sometimes, death. Persons older than 50 years of age have a higher risk of developing severe illness.
What is the best way to avoid mosquito bites?
The following personal protection measures are effective in reducing contact with mosquitoes:
- Wear long-sleeved shirts and long pants.
- Stay indoors at dawn and dusk when mosquitoes are most active.
- Use mosquito netting on baby carriages or playpens when your baby is outdoors.
- Make sure screens are repaired and that screens are tightly attached to doors and windows.
- Remove standing water from ditches, gutters, old tires, wheelbarrows and wading pools. Mosquitoes that bite people can begin to grow in any puddle or standing water that lasts for more than four days, so avoid letting water collect around your home.
- Avoid camping overnight near freshwater swamps to reduce your risk of exposure to mosquitoes that carry the EEE virus. If you do go camping, use a tent with mosquito netting and use appropriate repellents.
- Use mosquito repellents, making sure to follow directions on the label.
What should I do if I have a reaction to a repellent?
If you suspect that you or your child is having an adverse reaction to a repellent, wash the treated area, remove treated clothing, and call the Regional Center for Poison Control and Prevention serving Massachusetts and Rhode Island, toll-free at 800-222-1222.
If you go to the doctor, take the repellent with you — the label information may be useful to your physician.
Repellents containing DEET can be applied to exposed skin and clothing. Some DEET products may damage certain fabrics. Always read the label before applying. DEET is effective in repelling mosquitoes and other insects when used according to the manufacturer's recommendations.
Since DEET can be absorbed through the skin — and in rare cases causes illness — do not apply too much, do not apply to broken skin and do not apply to skin that will be covered by clothing.
Avoid applying in closed spaces, like cars or tents.
When using repellents on young children, do not apply to their hands or faces, as children often rub their eyes and faces and put their fingers in their mouths.
What precautions should I take with repellents?
The two most common active ingredients in repellents are DEET (N-N-diethyl-meta-toluamide) and permethrin.
These products will remain effective for many hours after application, so it is not necessary to frequently reapply them.
Choose a product that will provide protection for the length of time you will be exposed to mosquitoes.
Products containing DEET should not be used on children less than two months of age and should be used in concentrations of 30 percent or lower for older children and adults. Higher concentrations of DEET may provide protection for a longer period of time, but they do not provide better protection.
After returning indoors, wash treated areas with soap and water and launder treated clothing before reuse.
Permethrin-containing products are insecticides that kill mosquitoes and other insects on contact. Permethrin products are not designed to be applied to the skin. Clothing should be treated and allowed to dry in a well-ventilated area prior to wearing.
Because permethrin binds very tightly to fabrics, once the fabric is dry, very little of the permethrin gets onto the skin.
Links & Resources
For further information on EEE and West Nile Virus:
Massachusetts Department of Public Health
Division of Epidemiology and Immunization
888-658-2850 (toll free)
Massachusetts Department of Public Health
Center for Environmental Health
U.S. Environmental Protection Agency
Massachusetts Department of Agricultural Resources
State Reclamation and Mosquito Control Board