Molecular Epidemiology of Japanese Encephalitis Virus
Japanese encephalitis (JE) virus causes an encephalitic disease in humans that is characterized by a wide range of symptoms from a nonspecific febrile illness to convulsions, seizure, and death (Solomon et al. 2000). Approximately 30% of patients presenting at hospital with JE will succumb to the disease and about 50% of those who survive will have severe neurological sequelae (Solomon et al. 2000). The JE virus is carried by mosquitoes, primarily Culex species, and is endemic from tropical to temperate regions of Asia and Australasia. JE virus is generally considered to circulate in an endemic cycle in southern regions of Asia whereas the virus tends to have a more epidemic epidemiological pattern in northern Asia with outbreaks occurring during the summer months (Vaughn and Hoke 1992). The virus infects a number of animal hosts, most importantly pigs, which act as amplifying hosts and are found in high numbers throughout rural Asia. The first isolate of JE virus, and the prototype strain, was isolated in 1935 in Tokyo from a human brain and is designated the Nakayama strain. Since that time, a large number of JE virus isolates have been identified from a wide range of geographical locales throughout Asia, Indonesia, and most recently, northern Australia. Many of these viruses have been analyzed serologically and/or genetically to examine the distribution of the virus strains over both temporal and geographical boundaries. To date, the complete genome of 20 strains of JE virus have been sequenced including the first isolate from Australia (Williams et al. 2000).
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- Ali A, Igarashi A, Paneru LR, Hasebe F, Morita K, Takagi. M, Suwonkerd W, Tsuda Y, Wada Y (1995) Characterization of two Japanese encephalitis virus strains isolated in Thailand. Arch Virol 140: 1557–1575Google Scholar
- Ali A, Igarashi A (1997) Antigenic and genetic variations among Japanese encephalitis virus strains belonging to genotype 1 Microbiol Immunol 41: 241–252Google Scholar
- Chamberlain RW (1980) Epidemiology of arthropod-borne toga-viruses: the role of arthropods as hosts and vectors and of vertebrate hosts in natural transmission cycles. In: Schlessinger RW (ed) The Togaviruses. Academic Press, New York. pp 175–227Google Scholar
- Hori H (1986) Oligonucleotide fingerprint analysis on Japanese encephalitis (JE) virus strains of different geographical origins. Trop Med 28: 179–190Google Scholar
- Kimura-Korda J, Yasui K (1983) Topographical analysis of antigenic determinants on envelope glyco-protein V3 (E) of Japanese encephalitis virus, using monoclonal antibodies. J Virol 45: 124–132Google Scholar
- Kimura-Korda J, Yasui K (1986) Antigenic comparison of envelope protein E between Japanese en-cephalitis virus and some other flaviviruses using monoclonal antibodies. J Gen Virol 67: 2663–2672Google Scholar
- Mandl CW, Guirakhoo F, Holzman H, Heinz FX, Kunz C (1989) Antigenic structure of the flavivirus envelope protein E at the molecular level, using tick-borne encephalitis virus as a model. J Virol 63: 564–571Google Scholar
- Porterfield JS (1980) Antigenic characteristics and classification of Togaviridae. In: Schlessinger RW (ed) The Togaviruses. Academic Press, New York. pp 13–46Google Scholar
- Tsuchie H, Oda K, Vyythilingam I, Thayan R, Vijayamalar B, Sinniah M, Hossain MM, Kurimura T, Igarashi A (1994) Genetic study of Japanese encephalitis virus in Malaysia. Japan. J Med Sci Biol 47: 101–107Google Scholar