Japanese Encephalitis

Overview of Japanese Encephalitis

Japanese Encephalitis (JE) is a serious viral infection caused by the Japanese encephalitis virus (JEV), transmitted by mosquitoes, primarily in rural and agricultural areas of Asia. While most infected individuals remain asymptomatic, in severe cases, the disease affects the brain, leading to inflammation, neurological damage or even death. It is considered a major public health concern in endemic regions, especially during monsoon and post-monsoon seasons. Prevention through vaccination and mosquito control is crucial.

Types of Japanese Encephalitis

1. Asymptomatic Infection: Most common type; individuals show no signs of illness.

2. Mild Febrile Illness: Characterised by fever, headache, and malaise.

3. Severe Encephalitic Form: Involves brain inflammation, seizures, coma, or neurological deficits.

4. Japanese B Encephalitis: Another term often used to refer to Japanese Encephalitis virus infections.

Symptoms of Japanese Encephalitis

High fever and chills

Headache and neck stiffness

Confusion and disorientation

Vomiting and abdominal pain

Seizures, particularly in children

Tremors or involuntary movements

Coma in severe cases

Causes of Japanese Encephalitis

Caused by Japanese Encephalitis Virus (JEV), a flavivirus.

Transmitted by Culex mosquitoes, especially Culex tritaeniorhynchus.

Reservoir hosts include pigs and wading birds.

Common in areas with rice fields and standing water.

Complications in Japanese Encephalitis

Permanent neurological damage (e.g., cognitive deficits, movement disorders)

Paralysis or motor impairment

Hearing or speech loss

Behavioral and emotional disturbances

Coma or death in extreme cases

Risk Factors of Japanese Encephalitis

Living or traveling in rural endemic areas (Asia, Western Pacific)

Unvaccinated individuals in high-risk regions

Exposure during monsoon season

Occupation in farming or livestock handling

Young children and elderly are more vulnerable

Preventions of Japanese Encephalitis

Japanese Encephalitis Vaccination: Most effective prevention method

Avoid outdoor activities during dusk and dawn

Use mosquito repellents and protective clothing

Install mosquito nets and screens at home

Eliminate stagnant water near living areas

Ensure livestock is kept away from human dwellings