Prevention

The most effective way to prevent infection from ­­­Saint Louis Encephalitis virus is to prevent mosquito bites. Mosquitoes bite during the day and night. Use insect repellent, wear long-sleeved shirts and pants, treat clothing and gear, and take steps to control mosquitoes indoors and outdoors.

Protect yourself and your family from mosquito bites

a human hand pointing to the instructions on a can of insect repellent

Use Insect Repellent

Use Environmental Protection Agency (EPA)-registered insect repellentsExternal with one of the active ingredients below. When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women.

  • DEET
  • Picaridin (known as KBR 3023 and icaridin outside the US)
  • IR3535
  • Oil of lemon eucalyptus (OLE)
  • Para-menthane-diol (PMD)
  • 2-undecanone

Find the right insect repellent for you by using EPA’s search toolExternal.

Tips for babies and children

an adult male applying insect repellent to a child's face

  • Always follow instructions when applying insect repellent to children.
  • Do not use insect repellent on babies younger than 2 months old.
    • Instead, dress your child in clothing that covers arms and legs.
    • Cover strollers and baby carriers with mosquito netting.
  • Do not use products containing oil of lemon eucalyptus (OLE) or para-menthane-diol (PMD) on children under 3 years old.
  • Do not apply insect repellent to a child’s hands, eyes, mouth, cuts, or irritated skin.
    • Adults: Spray insect repellent onto your hands and then apply to a child’s face.

Tips for Everyone

  • Always follow the product label instructions.
  • Reapply insect repellent as directed.
    • Do not spray repellent on the skin under clothing.
    • If you are also using sunscreen, apply sunscreen first and insect repellent second.

Natural insect repellents (repellents not registered with EPA)

  • We do not know the effectiveness of non-EPA registered insect repellents, including some natural repellents.
  • To protect yourself against diseases spread by mosquitoes, CDC and EPA recommend using an EPA-registered insect repellent.
  • Choosing an EPA-registered repellent ensures the EPA has evaluated the product for effectiveness.
  • Visit the EPA website to learn more.External

clothing and gear being sprayed with insect repellent

Wear long-sleeved shirts and long pants

Treat clothing and gear

  • Use permethrin to treat clothing and gear (such as boots, pants, socks, and tents) or buy permethrin-treated clothing and gear.
    • Permethrin is an insecticide that kills or repels mosquitoes.
    • Permethrin-treated clothing provides protection after multiple washings.
    • Read product information to find out how long the protection will last.

    If treating items yourself, follow the product instructions.

  • Do not use permethrin products directly on skin.

a house

Take steps to control mosquitoes indoors and outdoors

  • Use screens on windows and doors. Repair holes in screens to keep mosquitoes outdoors.
  • Use air conditioning, if available.
  • Stop mosquitoes from laying eggs in or near water.
    • Once a week, empty and scrub, turn over, cover, or throw out items that hold water, such as tires, buckets, planters, toys, pools, birdbaths, flowerpots, or trash containers.
    • Check indoors and outdoors.

Prevent mosquito bites when traveling overseas

  • Choose a hotel or lodging with air conditioning or screens on windows and doors.
  • Sleep under a mosquito bed net if you are outside or in a room that does not have screens.
    • Buy a bed net at your local outdoor store or online before traveling overseas.
    • Choose a WHOPES-approved bed net: compact, white, rectangular, with 156 holes per square inch, and long enough to tuck under the mattress.
    • Permethrin-treated bed nets provide more protection than untreated nets.
      • Do not wash bed nets or expose them to sunlight. This will break down the insecticide more quickly.
    • For more information on bed nets, visit CDC’s page on insecticide-treated bed nets.
    • For more information on traveling overseas, visit Travelers’ Health.