Prevention

All travelers to Japanese encephalitis (JE) endemic areas should take precautions to avoid mosquito bites to reduce the risk for JE and other vector-borne infectious dis­eases. For some travelers who will be in a high-risk setting based on season, location, duration, and activities, JE vaccine can further reduce the risk for infection.

Avoid Mosquito Bites

• Use Insect Repellent. When you go outdoors, use an EPA-registered insect repellent such as those containing DEET, IR3535, picaridin or oil of lemon eucalyptus. Even a short time outdoors can be long enough to get a mosquito bite. For more information about insect repellents, see Protection against Mosquitoes, Ticks, & Other Insects & Arthropods.
• Wear Proper Clothing to Reduce Mosquito Bites. When weather permits, wear long-sleeves, long pants and socks when outdoors. Mosquitoes may bite through thin clothing, so treating clothes with repellent containing permethrin or another EPA-registered repellent will give extra protection. Don’t apply repellents containing permethrin directly to skin.
• Reduce Exposure to Mosquitoes During Peak Biting Hours. The mosquitoes that transmit JE virus feed mainly outside during the cooler hours from dusk to dawn. Travelers to high risk areas should consider minimizing outdoor activities at these times if possible. To reduce the risk of JE and other vector-borne diseases, travelers should stay in air-conditioned or well-screened rooms, or use a bed net and aerosol room insecticides.

Obtain Vaccine if Recommended

• JE vaccine is recommended for travelers who plan to spend 1 month or more in endemic areas during the JE virus transmission season. This includes long-term travelers, recurrent travelers, or expatriates who will be based in urban areas but are likely to visit endemic rural or agricultural areas during a high-risk period of JE virus transmission.
• Vaccine should also be considered for the following:
  • Short-term (less than 1 month) travelers to endemic areas during the transmission season, if they plan to travel outside an urban area and their activities will increase the risk of JE virus exposure. Examples of higher-risk activities or itineraries include: 1) spending substantial time outdoors in rural or agricultural areas, especially during the evening or night; 2) participating in extensive outdoor activities (such as camping, hiking, trekking, biking, fishing, hunting, or farming); and 3) staying in accommodations without air conditioning, screens, or bed nets.
  • Travelers to an area with an ongoing JE outbreak.
  • Travelers to endemic areas who are uncertain of specific destinations, activities, or duration of travel.
• JE vaccine is not recommended for short-term travelers whose visits will be restricted to urban areas or times outside a well-defined JE virus transmission season.
• More information about JE vaccine.