Encephalitis

What is encephalitis?

Encephalitis is an inflammation caused by a viral infection. The specific viruses involved may vary and although exposure to viruses can occur through insect bites, food or drink, or skin contact, travelers are most at risk to exposure from insect bites. In rural areas, arboviruses that are carried by mosquitoes or ticks are the most common cause of infection.

While there have been outbreaks in recent years in the United States of several forms of encephalitis, such as West Nile encephalitis and St. Louis encephalitis, travelers abroad are most at risk for Japanese encephalitis and tickborne encephalitis.

How can Japanese encephalitis be prevented?

A vaccine for Japanese encephalitis is currently available in the United States through most travelers’ clinics. The Centers for Disease Control and Prevention (CDC) generally recommends the vaccine only for persons who will travel in rural areas for four weeks or more, except for circumstances where there is a known outbreak of Japanese encephalitis.

In addition, travelers should take precautions to prevent insect bites, including the following:

• Minimize outdoor exposure during the cooler hours at dusk and dawn, when mosquitoes that transmit the disease feed.
• Wear mosquito repellents containing DEET as an active ingredient.
• Stay in air conditioned or well-screened rooms.

In addition, travelers to rural areas should bring a portable bednet and apply permethrin, a mosquito repellent/insecticide to clothing.

Treatment for arbovirus encephalitis:

There is no specific treatment for encephalitis and treatment is generally supportive with maintenance of respiratory and circulatory support while the infection runs its course. Specific treatment for encephalitis will be determined by your physician based on:

• your age, overall health, and medical history
• extent of the disease
• your tolerance for specific medications, procedures, or therapies
• expectations for the course of the disease
• your opinion or preference