Outlook on Japanese Encephalitis

[ Bunar Tamin and Martha Pasar ]
Japanese encephalitis (JE) is an apparent to acute arthropod borne viral infection of the central nervous system characterised in man by fever, headache, prostration, neck rigidity and altered sensorium.
The infection is inapparent in animals, particularly pigs and birds.
A large scale outbreak was reported in 1973 from Bankura and Burdwan districts of West Bengal. According to the World Health Organization (WHO), 24 countries in Southeast Asia and the Pacific region suffer from JE transmission risk, covering more than three billion people overall worldwide.
JE is caused by a flavivirus. The virus is passed from animal to human through the bite of an infected mosquito. Pigs and wading birds are the main carriers of the JE virus. A mosquito becomes infected after sucking the blood from an infected animal or birds, and if you get bitten by an infected mosquito, it can pass on the virus.
Mosquitoes that carry JE usually breed in rural areas, particularly where there are flooded rice fields or marshes, although infected mosquitoes have also found in urban areas. They usually feed between sunset and sunrise.
Fever, headache, neck rigidity are the symptoms seen in human. However, most cases of JE do not show any symptoms and JE cannot be passed from person to person.
In animal, symptoms of JE are fever, inability to walk, teeth grinding. Signs begin to show between 8 to 10 days after exposure to the virus.
A fairly accurate clinical diagnosis is possible only during large scale epidemics. Laboratory diagnosis of JE is made by isolation of virus from autopsy specimens of brain tissues. In the absence of reliable antiviral drug, treatment using antipyretic and anticonvulescent drugs with proper management is advised. Maintenance of electrolytes balance and reducing of intracranial pressure is also advisable.
JE is spread primarily by the culex mosquito. It is important to remain protected from these mosquitoes, both indoors and outdoors. Before stepping out, the use of personal repellents like fabric roll-ons can prevent mosquito bites when at home. Shutting the doors and windows in the evening and using household-level repellents help keep mosquitoes away through the night. People should also sleep under bed nets for further protection and getting vaccinated before travelling is recommended.
(The contributors are 3rd year students of the College of Veterinary Sciences and Animal Husbandry, Aizawl.)