The Japanese Encephalitis Virus Evolution and Epidemiology

Abstract

The virus that causes Japanese encephalitis (JEV) is the cause of Japanese encephalitis (JE), a potentially fatal brain infection contracted via mosquito bites. The Japanese encephalitis virus, which is endemic in 24 countries and poses a threat to nearly 3 billion people, is the primary Asia's viral encephalitis cause. An estimated one hundred thousand clinical cases and 25,000 fatalities occur worldwide each year. Travelers to endemic areas must be vaccinated, even though Arab nations are still outside the transmission zones. Prevention: Inactivated (IXIARO), live attenuated (IMOJEV, CD. JEVAX), and Indian (JENVAC) vaccine formulations are among the WHO-prequalified vaccinations. Dosage, target populations, and contraindications vary for each. Although the effectiveness of current vaccines may be threatened by developing genotype V, sustained immunizations has reduced endemic countries by 73–100%. To rule out flavivirus cross-reactivity, primary diagnosis is made by IgM capture ELISA in serum/CSF (WHO-recommended), followed by confirmatory PRNT at reference laboratories. Because of temporary viraemia, RT-PCR is restricted in its ability to diagnose humans, although it is beneficial for surveillance. Socio-environmental Factors, historically recorded during the Korean War (402 US cases, 1950), social instability (war, displacement, and health system collapse) increases burden by disrupting immunization, weakening surveillance, and increasing vector exposure.