Planning a trip to Asia? You are no doubt already dreaming of scenic landscapes, rich cultural experiences and exotic foods.

Many Asian countries boast warm, balmy climates and high levels of rainfall. There’s often no cold season to speak of, allowing for year-round breeding for pests of the buzzing variety—like mosquitos. And these pests may carry viruses that are transmittable to humans, including Japanese encephalitis.

Mosquitos and humans have a long and sordid past.

They’ve been human-kind’s constant companion since the beginning of time. In the U.S., most of us just put out citronella candles and accept them as a nuisance.

But in many regions of the world, including Asia, changes in climate conditions, population growth and urban sprawl have led to increases in mosquito breeding grounds, especially in urban and semi-urban areas. And if you’re visiting one of these idyllic locations, you should know that the mosquito you’ll encounter is not your backyard variety.

More than just a bug bite

Like Zika and West Nile viruses, the Japanese encephalitis (JE) virus is spread to humans through the bite of an infected mosquito, and the infection can have devastating consequences. Unlike Zika and West Nile, you’ve probably never heard of it.

One reason is this: in many Asian countries, JE vaccination is routine. Just like people in the United States receive the measles, mumps and rubella protection as children, most people in JE-risk regions are often protected with a vaccine.

And don’t let the name fool you—Japanese encephalitis isn’t only found in Japan. Cases have been reported in more than 20 countries in Asia and parts of the western Pacific. In fact, despite those local vaccine programs, there are approximately 68,000 cases of JE every year (and that’s just what’s reported). But most visitors to these regions haven’t been told about JE and aren’t protected.

Suffering the most serious consequences of the JE virus is rare: many may only experience mild flu-like symptoms and might not even realize that it’s due to the virus. Some, however, will suffer more serious – even fatal – consequences, including brain swelling or stroke-like symptoms that can result in permanent neurological damage.

Plan for good health

Whether you’re the type of traveler who plans your itinerary to the letter, or one who likes to let spontaneity be your guide, it’s important to plan for a healthy visit by brushing up on some basic steps to avoid exposure to local mosquitos.

While there is no cure for JE, it can be prevented by taking steps to avoid mosquito bites, and with vaccination.

Prevention strategies you should consider

Try to avoid mosquitoes!
Mosquitoes are most active during the cooler hours from dusk to dawn. Limit the amount of time spent outsides or with exposed skin during these hours.

• Use EPA-registered insect repellent, such as those containing DEET, IR3535, picaridin or oil of lemon eucalyptus.
• Wear protective clothing that covers as much of your skin as possible, such as long sleeves, pants and high socks when outdoors.
• Carry a mosquito net. Not every hotel off the beaten path (or on!) will supply bed and window netting. Plan ahead and pack your own bed net to avoid surprises.

Vaccinate if you are at risk

• Do you travel frequently to Asia, are planning a long trip (e.g., a month), or will you be taking up residence?
• Is it possible you might participate in unplanned excursions and/or activities (i.e., something you would learn about once you’re there)?
• Will you be spending time outdoors (day or night) exploring, hiking, fishing, biking, camping, etc.?
• Is there a chance you’ll be staying in accommodations without air conditioning, screens or bed nets?

If you answered yes to any of the above, according to the Centers for Disease Control and Prevention vaccination might be right for you. See a travel health provider to find out for sure.

Taking a few extra steps to stay healthy, along with a visit to a travel health provider, will leave you resting easy on the adventure of a lifetime.

To find a travel health provider near you click here.

This article is sponsored by Valneva USA, Inc. To learn more about Japanese encephalitis and how to protect yourself, visit www.preventje.com.

SOURCES

Balogun EO, Nok AJ, et al. Global warming and the possible globalization of vector-borne diseases: a call for increased awareness and action. Trop Med Health. 2016;44:38. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5121979/. Accessed October 11, 2022.

Heffelfinger JD, Li X, Batmunkh N, et al. Japanese encephalitis surveillance and immunization – Asia and Western Pacific regions, 2016. Morb Mortal Wkly Rep. 2017;66(22):579-583.

Centers for Disease Control and Prevention. Yellow Book 2020, Chapter 3. https://wwwnc.cdc.gov/travel/yellowbook/2020/noninfectious-health-risks/mosquitoes-ticks-and-other-arthropods. Updated July 2, 2019. Accessed October 11, 2022.

Centers for Disease Control and Prevention. Japanese encephalitis vaccine. https://www.cdc.gov/japaneseencephalitis/vaccine/index.html. Reviewed June 17, 2022. Accessed October 11, 2022.