Subject(s)
Communicable Diseases, Emerging/epidemiology , Communicable Diseases, Emerging/virology , Encephalitis Virus, Japanese , Encephalitis, Japanese/epidemiology , Encephalitis, Japanese/virology , Communicable Diseases, Emerging/history , Encephalitis, Japanese/history , History, 21st Century , Incidence , Population Surveillance , Republic of Korea/epidemiologyABSTRACT
Japanese encephalitis virus (JEV) consists of five genotypes (GI-V). Phylogenetic characterization of 16 JEV strains isolated from the 'USSR', Japan and Korea during the 1930-1970s revealed that 15 strains fell into GIII, confirming that GIII was the predominant genotype of JEV in Japan and Korea between 1935 (isolation of the prototype strain; a GIII virus) and the 1990s (when GI supplanted GIII). One of the Korean isolates fell into GII, demonstrating that GII has been circulating for at least 19 years longer than previously thought. Formerly, GII was associated with endemic disease and this genotype had never been isolated north of Southern Thailand. Additionally, the northern border of GIII prevalence was extended from Japan to the 'USSR'.
Subject(s)
Encephalitis Virus, Japanese/genetics , Encephalitis, Japanese/epidemiology , Encephalitis, Japanese/virology , RNA, Viral/genetics , Asia/epidemiology , Cluster Analysis , Encephalitis Virus, Japanese/isolation & purification , Encephalitis, Japanese/history , Endemic Diseases , Genotype , History, 20th Century , Humans , Molecular Epidemiology , Molecular Sequence Data , Phylogeny , Sequence Analysis, DNA , Sequence Homology , USSR/epidemiologySubject(s)
Communicable Diseases, Emerging/epidemiology , Encephalitis, Japanese/epidemiology , Communicable Diseases, Emerging/history , Communicable Diseases, Emerging/prevention & control , Encephalitis, Japanese/history , Encephalitis, Japanese/prevention & control , Global Health , History, 21st Century , Humans , Japanese Encephalitis Vaccines/administration & dosageABSTRACT
Japanese encephalitis (JE), a vector-borne viral disease, is endemic to large parts of Asia and the Pacific. An estimated 3 billion people are at risk, and JE has recently spread to new territories. Vaccination programs, increased living standards, and mechanization of agriculture are key factors in the decline in the incidence of this disease in Japan and South Korea. However, transmission of JE is likely to increase in Bangladesh, Cambodia, Indonesia, Laos, Myanmar, North Korea, and Pakistan because of population growth, intensified rice farming, pig rearing, and the lack of vaccination programs and surveillance. On a global scale, however, the incidence of JE may decline as a result of large-scale vaccination programs implemented in China and India.
