Like Zika and West Nile, Japanese encephalitis (JE) is a potentially serious disease caused by a virus spread to humans through the bite of an infected mosquito. Unlike Zika and West Nile, you’ve probably never heard of it.

What is JE?

As its name implies, JE is a form of encephalitis, or inflammation of the brain, caused by the JE virus found across parts of Asia and the western Pacific. Most people infected by JE virus suffer mild, flu-like symptoms or are asymptomatic; however, in some cases the infection results in JE and the outcome can be very serious.

JE is rare, but for those who do contract the disease, the effects could be lifelong or even fatal. Up to 30 percent of people who develop JE do not survive, and of those who do, up to half suffer serious long-term complications, which can include neurological, cognitive, and psychiatric impairment. While there is no specific treatment, it can be prevented with personal protective measures to prevent mosquito bites and vaccination.

A recent survey of 776 U.S. adults who had traveled to Asia in the past 24 months found that about 50 percent of them were unaware that JE existed or of the possible consequences of contracting JE – even though the vast majority of those surveyed would be considered at increased-risk for exposure to JE virus based on their travel plans.

Who is at risk?

The risk of JE is low for travelers to Asia but can vary based on several factors, such as their activities, where they spend time (such as outside urban areas), and their duration of travel.

Destination, Tokyo? You should still talk to a qualified travel health professional about your potential risk. The same survey of travelers to Asia found that 72 percent of respondents visited at least one area or participated in an activity that put them at increased risk for exposure to JE virus. Such activities included hiking/trekking, bicycling, camping, and visiting areas away from major cities such as rural areas, national parks, beach resorts or wilderness/jungle areas.

How is it treated?

Prevention is key!

There is no cure for JE, and once diagnosed, medical interventions are focused around easing symptoms and providing supportive care. Because of this, the best protection against JE is prevention – which can take the form of mosquito netting, long-sleeve shirts and pants, insect repellent (always choose an EPA-registered insect repellent), staying in places with air conditioned or screened rooms, and keeping your outdoor activities to a minimum, especially during peak biting hours: from dusk to dawn. Lastly, vaccination is also an option.

What can I do?

A visit to a travel health professional well in advance of your trip (at least 30 days) is a good idea to help understand your risk of exposure to JE and simple measures you can take to protect your health. Take simple steps to avoid mosquito bites and, depending on the time of year, length of stay, regions visited, and itinerary, vaccination might also be advised.

As the saying goes, an ounce of prevention is worth a pound of cure – while rare, the effects of JE have the potential to be lifelong or even fatal. Protect yourself with a visit to a qualified travel health professional before your next trip! Find one here.