Japanese Encephalitis is a rare illness caused by the Japanese Encephalitis Virus (JEV). This flavivirus, related to the viruses that cause Dengue Fever, Yellow Fever, and Zika, often infect pigs and birds in rural and agricultural locations. Mosquitoes carry the virus from one animal to another and, unfortunately, to an occasional human.
Those who are planning trips to countries where the virus is present should visit Dr. Klapowitz at Travel Medicine Consultations to receive the Japanese Encephalitis vaccine NYC residents need to stay safe and healthy throughout their travels.
What are the symptoms of Japanese Encephalitis?
Most people infected by the JEV have no symptoms. After an incubation period of 5-15 days, some people develop only a mild headache and fever.
Less than 1% of people infected by the Japanese Encephalitis Virus actually develop encephalitis signs and symptoms, which include:
- High fever
- Severe headaches
- Neck stiffness
Of people who develop encephalitis, 20-30% die. Among those who survive, 30-50% are left with serious long-term neurologic issues (CDC Yellow Book)
Places where Japanese Encephalitis is common:
The Japanese Encephalitis virus is common in rural and agricultural areas. In some countries, the presence of JEV varies with the season and rainfall. In others, it is present all year round. According to the WHO (World Health Organization) there are 24 countries where the disease is endemic. These countries are clustered in Southeast Asia and Western Pacific regions.
In the past, Korea, Japan, Taiwan, China, and Thailand have all had outbreaks of the disease. These countries have controlled the outbreak with vaccinations. Nations such as Myanmar, Malaysia, India, Nepal, Vietnam, and Cambodia are still experiencing outbreaks. Isolated outbreaks have been seen in mainland Australia, and a few cases have even been reported in the United States.
Japanese Encephalitis Vaccine and Prevention:
Since there is no treatment for Japanese Encephalitis, and it can be a deadly disease, prevention measures are important. Mosquito avoidance is vital. In the United States, Ixiaro is the only vaccine available. A series of two Ixiario injections is given at least one week apart in adults aged 18 to 65 and one month apart in children and teens under age 18.