Japanese encephalitis: All you need to know about the viral disease

Zee Media Bureau

New Delhi: Japanese encephalitis is a serious mosquito-borne viral infection, and leads to inflammation of brain. 

Formerly known as Japanese B encephalitis, the condition is caused by the Japanese encephalitis virus (JEV), a flavivirus and belongs to the same genus as dengue, yellow fever and West Nile viruses. As per the World Health Organisation (WHO), the diseases occurs many parts of Asia with an estimated 68 000 clinical cases every year.

Meanwhile, the disease has claimed three lives in the northeastern state of Manipur last week, and over 295 JE positive cases have been reported from Assam with 66 casualties so far.

The incubation period of JEV (time from infection until illness) is typically 5-15 days, but 1 in 250 infections develop into encephalitis.

Initial symptoms of JEV include fever, headache, vomiting, changes in mental status, neurologic symptoms, weakness, and movement disorders might develop over the next few days. Seizures are common, especially among children.

There is no cure or specific treatment found to benefit patients with JE. Treatment methods include rest, fluids, pain relievers and medication to relieve the symptoms and overcome the infection.

According to CDC, among patients who develop encephalitis, 20% - 30% die. Although some symptoms improve after the acute illness, 30%-50% of survivors continue to have neurologic, cognitive, or psychiatric symptoms.

While safe and effective vaccines are available to prevent the disease, all travellers to the JE endemic areas should take precautions to avoid mosquito bites to reduce the risk for JE. Preventive measures may include -

• Use of insect repellents, bed nets to avoid mosquito and other insect bites
• Wearing long-sleeved clothes to reduce mosquito bites
• Reducing exposure to mosquitoes during peak biting hours
• Vaccination – travellers spending extensive time in JE endemic areas are recommended to get vaccinated.