New Delhi: According to a release issued by the National Health Mission on Saturday (July 16, 2022), the Japanese Encephalitis (JE) virus has claimed four more lives in Assam, taking the death toll this month to 27. All the four deaths have been reported from Jorhat district. The state also reported nine fresh cases on Saturday, taking this month’s tally to 169.
Three cases were reported from Golaghat district, two each from Sibsagar and Sonitpur and one each from Goalpara and Kokrajhar districts. Earlier, four deaths and 16 new cases of Japanese encephalitis were reported in Assam on Friday.
What is Japanese Encephalitis Virus?
Japanese encephalitis virus is a mosquito-borne flavivirus and belongs to the same genus as dengue, yellow fever and West Nile viruses. It is the most important cause of viral encephalitis in Asia and the first case of Japanese encephalitis viral disease was reported in Japan in 1871.
According to the World Health Organization (WHO), approximately 68,000 clinical cases of Japanese encephalitis are reported globally each year, with approximately 13,600 to 20,400 deaths.
Japanese encephalitis primarily affects children and most adults in endemic countries have natural immunity after childhood infection, but individuals of any age can be affected.
Signs and symptoms of Japanese encephalitis disease
According to the WHO, most Japanese encephalitis infections are mild (fever and headache) or without obvious symptoms, but about 1 in 250 infections result in severe clinical illness. The incubation period is between 4-14 days.
In children, gastrointestinal pain and vomiting may be major early symptoms. Severe illness has a rapid onset of high fever, headache, stiff neck, disorientation, coma, seizures, spastic paralysis, and eventually death. The case-mortality rate in people with symptoms can be as high as 30%.
Of those who survive, 20%–30% suffer permanent intellectual, behavioral or neurological sequelae such as paralysis, recurrent seizures, or an inability to speak.
transmission of Japanese encephalitis
Japanese encephalitis is transmitted to humans by the bite of infected mosquitoes of the Culex species (mainly Culex tritaenorhynchus). Humans, once infected, do not develop enough viremia for mosquitoes to feed on.
The virus is present in the transmission cycle between mosquitoes, pigs and/or water birds (enzootic cycle). The disease is mainly found in rural and periurban settings, where humans live close to these vertebrate hosts.
In most temperate regions of Asia, Japanese encephalitis virus is mainly transmitted during the warm season, when major epidemics can occur. In tropical and subtropical regions, transmission can occur year-round but often intensifies during the rainy season and the pre-harvest period in rice-growing areas.