Japanese encephalitis virus
Last reviewed: 23.04.2024
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Japanese encephalitis is a natural focal infectious disease transmitted by mosquitoes of the genus Culex and other genera of the Culicinae subfamily. For the first time the virus was isolated in 1933 by the Japanese scientist M. Hayashi, in Russia it was first isolated in 1938 during the work of the complex expedition in Primorye by AK Shubladze (1940) and AA Smorodintsev and VD Neustroev (1941). The disease of Japanese encephalitis is common in the south of East Asia, especially in Japan, where the incidence often reaches 250 per 100 000 population. In Russia, Japanese encephalitis is registered in the southern regions of Primorye. In nature, the virus persists not only in arthropods, but also in various species of birds and bats. Diseases of Japanese encephalitis are detected exclusively in the summer-autumn period. This is one of the most serious diseases with the highest lethality, ranging from 20 to 70 and even 80%, more often in the elderly and women.
The basis of pathogenetic mechanisms is the lesions of the vascular system both in the central nervous system and in all organs and tissues, where the virus intensively multiplies and spreads by the hematogenous way. The incubation period is from 4 to 14 days.
The disease begins very keenly: the temperature is 39 ° C or higher, the consciousness is disturbed, coma, mental disorders often arise.
Death can come already within the first few hours. With a more favorable current, convulsions develop, generalized muscle strain, paralysis. An acute period, from the very beginning of which there is a meningeal syndrome, lasts no more than 8-9 days. The terminal stage of the disease is characterized by injuries to vital stem cells and bulbar disorders.
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