What is encephalitis? Encephalitis is an inflammation of the
brain that is frequently caused by a viral infection. The
viruses are called arboviruses and are transmitted to people and
animals by insects. In rural areas, arboviruses that are carried
by mosquitoes or ticks are the most common cause of arboviral
infection, which is often mild, but can progress to
encephalitis. 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. What is Japanese encephalitis? Japanese
encephalitis is a mosquito-borne viral disease that occurs
mainly in: China, Japan, and Korea Japanese encephalitis also
occurs at a lower frequency in Taiwan, Singapore, and Hong Kong.
In all of these areas, Japanese encephalitis is primarily a
rural disease. Occurrence of the disease is quite low. On
average, among persons who are infected by a mosquito