Mosquito Safety

Protection Against Mosquitoes

  • Avoid places and times when mosquitoes bite. Generally, peak biting periods for the type of mosquitoes capable of transmitting WNV occur just before and after sunset and just before dawn.
  • Apply insect repellent containing 25-35% DEET when you're outdoors.
  • Assure door and window, patio and porch screens are tight-fitting and in good repair.
  • Wear long-sleeved tops, long pants, socks and shoes and clothing made of tightly woven materials to keep mosquitoes away from skin. Light colored clothing is best.
  • Eliminate stagnant water in bird baths, ponds, flower pots/trays/saucers, water fountains and water features and get rid of tires, buckets or other receptacles that could serve to contain water where mosquitoes might breed.
  • Be sure to check clogged gutters and flat roofs that may have poor drainage.
  • Make sure cisterns, cesspools, septic tanks, rain barrels and trash containers are covered tightly with a lid or with 16-mesh screen.
  • Level the ground around residence so water can run off and not collect in low spots. Fill in holes or depressions near the building that accumulate water.
  • Fill in tree rot holes and hollow stumps that hold water.
  • Stock ornamental water gardens with fish (e.g. minnows, "mosquito fish" or goldfish) that eat mosquito larvae.
  • Treat small pools of water with "Bti", a bacterial insecticide. Many hardware stores carry doughnut-shaped Bti briquettes (Mosquito Dunks) for this purpose. Be sure to follow the insecticide label exactly.
  • Keep weeds and grass cut short; adult mosquitoes look for these shady places to rest during the hot daylight hours.
  • Bird and wild game hunters should follow the usual precautions when handling wild animals and birds. They should wear gloves when handling and cleaning birds or animals to prevent blood exposure to bare hands.

    West Nile Virus - Transmission, Signs & Symptoms

    People become infected by the bite of a mosquito infected with West Nile Virus. Mosquitoes become infected when they feed on infected birds, which may circulate the virus in their blood for a few days. Infected mosquitoes can then transmit WNV to humans and animals while biting to take blood. The virus is located in the mosquito's salivary glands. During blood feeding, the virus may be injected into the animal or human where it may multiply possibly causing illness. West Nile encephalitis is NOT transmitted from person-to-person. There is no evidence that a person can get the virus from handling live or dead infected birds. However, persons should avoid bare-handed contact when handling any dead animals and use gloves or double plastic bags to place the carcass in a garbage can.

    Most people infected with West Nile virus have no clinical symptoms of illness, but may become ill 3-15 days after the bite of an infected mosquito. Infections can be mild and include fever, headache, body aches, and occasionally with skin rash and swollen lymph glands. Sever symptoms are marked by headache, high fever, neck stiffness, stupor, convulsions, muscle weakness, paralysis and, rarely, death. It is assumed that if a person contracts West Nile virus they develop a lifelong natural immunity to future infection, but it may weaken in later years. While everyone is at risk of West Nile disease, those at highest risk are persons 50 years of age or older.

    Using Insect Repellants Safely

    Insect repellents help people reduce their exposure to mosquito bites that may carry potentially serious viruses such as West Nile virus, and allow them to continue to play and work outdoors. Many of the mosquitoes that carry the West Nile virus are likely to bite around dusk and dawn. Female mosquitoes bite people and animals because they need the protein found in blood to help develop their eggs. Mosquitoes are attracted to people by skin odors and carbon dioxide from breath. Repellents contain a chemical, which does not kill, but repels the mosquito and are effective only at short distances from the treated surface, so you may see mosquitoes flying nearby. When using repellents be sure to follow the directions on the product to determine how frequently you need to reapply repellent. Sweating, perspiration or getting wet may mean that you need to re-apply repellent more frequently. Repellents containing a higher concentration of active ingredient, such as DEET, provide longer-lasting protection. If you are no longer getting bites, there is no reason to apply more repellent. A product containing 23.8% DEET can provide an average of 5 hours of protection from mosquito bites.

    Guidelines for Repellant Use

  • Use enough repellent to cover exposed skin or clothing. Don't apply repellent to skin that is under clothing. Heavy application is not necessary to achieve protection
  • Do not apply repellent to cuts, wounds, or irritated skin
  • After returning indoors, wash treated skin with soap and water
  • Do not spray aerosol or pump products in enclosed areas.
  • Do not apply aerosol or pump products directly to your face. Spray your hands and then rub them carefully over the face, avoiding eyes and mouth
  • It is recommended that for children under 2 years of age only one application per day of repellent containing DEET should be used.
  • When using repellent on a child, apply it to your own hands and then rub them on your child. Avoid children's eyes and mouth and use it sparingly around their ears
  • Do not apply repellent to children's hands. (Children tend to put their hands in their mouth
  • Do not allow young children to apply insect repellent to themselves; have an adult do it for them. Keep repellents out of reach of children
  • If repellent is applied to clothing, wash treated clothing before wearing again.

    There are no reported adverse reactions following use of repellents containing DEET in pregnant or breastfeeding women. In rare cases, these products may cause skin reactions.