Molecular epidemiological analysis of Japanese encephalitis virus in China

1 State Key Laboratory for Infectious Disease Prevention and Control, Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 100 YingXinJie, XuanWuQu, Beijing 100052, People's Republic of China 2 Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan 3 Department of Arbovirus and Chlamydia, Yunnan Institute of Endemic Diseases Control and Prevention, 33 Wenhua Rd, Dali City 67100, Yunnan Province, People's Republic of China 4 Department of Virology, Guizhou Province Center for Disease Control and Prevention, 73 BaGeYanLu, GuiYang City 550004, Guizhou Province, People's Republic of China 5 Department of Virology, Henan Province Center for Disease Control and Prevention, 47 WeiWuLu, Zhengzhou City 450003, Henan Province, People's Republic of China 6 Department of Virology, Sichuan Province Center for Disease Control and Prevention, 40 HuaiShuJie, Chendu City 610031, SiChuan Province, People's Republic of China 7 Chinese Center for Disease Control and Prevention, 29 NanWeiLu, XuanWuQu, Beijing 100050, People's Republic of China Correspondence Guo Dong Liang gdliang{at}hotmail.com Sixty-two new Japanese encephalitis virus (JEV) isolates were obtained from mosquitoes, biting midges, human cerebrospinal fluid and human blood samples in China during 2002–2005. The E and prM genes were sequenced and phylogenetic analyses were performed with 38 JEV other isolates from China and 36 JEV strains from other countries. Phylogenetic trees based on the E and prM gene sequences were similar. The results indicate that: (i) recent JEV isolates from China are divided into two genotypes, genotype 1 and genotype 3; (ii) recent JEV isolates from China are grouped into the same clusters within genotypes 1 and 3; and (iii) genotype 1 JEV strains have been isolated in China since 1979, whilst genotype 3 JEV strains were isolated before the 1970s. The results suggest that genotype 1 JEV was introduced to China around 1979 and that JEV strains belonging to genotypes 1 and 3 circulate in China.