Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Molecular epidemiology of Japanese encephalitis virus circulating in South Korea, 1983-2005 | Yun et al. Virology Journal 2010 7 127 http content 7 1 127 VIROLOGY JOURNAL SHORT REPORT Open Access Molecular epidemiology of Japanese encephalitis virus circulating in South Korea 1983-2005 Seok-Min Yun Jung Eun Cho Young-Ran Ju Su Yeon Kim Jungsang Ryou Myung Guk Han Woo-Young Choi and Young Eui Jeong Abstract We sequenced the envelope E gene of 17 strains of the Japanese encephalitis virus JEV isolated in South Korea in 1983-2005 and compared the sequences with those from previously reported strains. Our results show the remarkable genetic stability of the E gene sequence in Korean JEV strains. Five pairs of E gene sequences from 10 Korean strains were identical despite geographical differences and a maximum five-year time span. Sequence comparisons with other Asian strains revealed that the Korean strains are closely related to those from China Japan and Vietnam. Genotype 3 strains were predominant in Korea before 1993 when genotype 1 strain K93A07 was first isolated. The two genotypes were detected simultaneously in 1994 but since then only genotype 1 has been isolated in South Korea. Thus the genotype change occurred according to the year of isolation rather than the geographical origin. Findings Japanese encephalitis virus JEV is a mosquito-borne fla-vivirus genus Flavivirus family Flaviviridae which causes acute viral encephalitis in humans. Approximately 30 000-50 000 cases with 10 000 deaths are reported annually throughout Asia 1 . The JEV genome is a positive-sense single-stranded RNA molecule approximately 11 kb in length. The polyprotein is processed into three structural proteins the capsid C membrane M and envelope E proteins and seven nonstructural proteins NS1 Ns2A Ns2B NS3 NS4A NS4B and NS5 2 . Generally RNA viruses have intrinsically high mutation rates and consequently greater potential for rapid evolution than the DNA viruses 3 . Many studies have revealed the phylogenetic relationships among the JEV strains. Although .
