JAPANESE ENCEPHALITIS

Japanese Encephalitis: Overview, Symptoms, Transmission, Prevention, and Immunization

Overview: Japanese encephalitis is the primary cause of viral encephalitis in Asia, caused by a flavivirus. It often presents with symptoms like shivering, malaise, and fever. While many infections are asymptomatic, clinical cases can lead to severe neuropsychic issues.

Symptoms: Symptoms include sudden fever, shivering, severe headaches, stupor, confusion, and vegetative disorders. Mortality among clinical cases ranges from 20 to 50%, and survivors may experience conditions like epilepsy, ataxia, or behavioral disorders.

Transmission: Transmitted by Culex mosquitoes, Japanese encephalitis primarily infects domestic pigs, mammals, and marsh birds. Mosquitoes thrive in rural areas, biting at dawn or dusk. Human transmission is occasional, with an estimated 1 in 2,500 mosquito bites transmitting the disease. The incubation period is approximately one week.

Prevention: Standard mosquito precautions are essential, including insect repellent, bed netting, and wearing light-colored, long-sleeve clothing. The risk is minimal, with only a few reported cases among Americans in endemic regions since 1981.

Immunization: Vaccination is recommended for travelers aged 18 and older planning to stay in endemic areas for at least one month, especially during the rainy season. The vaccine is administered in two shots on days 0 and 28. Side effects, experienced by 10-20% of vaccinated individuals, may include headaches, muscle pain, fever, and malaise.

Note: Consult a healthcare provider for comprehensive pre-travel advice and vaccination recommendations. More information is available in the Essential Information for a Safe Trip guide.