Surveillance of Japanese encephalitis virus infection in mosquitoes in Vietnam from 2006 to 2008.
Japanese encephalitis virus (JEV) infection in mosquitoes was monitored in Vietnam from 2006 to 2008. A total of 15,225 mosquitoes, identified as 26 species in five genera were collected and 12,621 were grouped into 447 pools for examination of JEV infection by assays for cytopathic effects in C6/36 cells and by RT-PCR to detect flavivirus RNA. Three JEV strains were isolated from Culex tritaeniorhynchus Giles collected in northern and southern Vietnam and two JEV strains were isolated from Culex vishnui Theobald collected in the highlands of Vietnam. Genetic and phylogenetic analyses, based on complete E gene nucleotide sequences, revealed that the five JEV strains were classified into the genotype I group and six amino acid differences were found in these five strains. These results indicated that multiple JEV genotype I populations are circulating countrywide in Vietnam, transmitted by bites of their Cx. tritaeniorhynchus and Cx. vishnui.
Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan.
Ryusei
R
Kuwata
Phan Thi
PT
Nga
Nguyen Thi
NT
Yen
Keita
K
Hoshino
Haruhiko
H
Isawa
Yukiko
Y
Higa
Nguyen Vet
NV
Hoang
Bui Minh
BM
Trang
Do Phuong
do P
Loan
Tran Vu
TV
Phong
Toshinori
T
Sasaki
Yoshio
Y
Tsuda
Mutsuo
M
Kobayashi
Kyoko
K
Sawabe
Masahiro
M
Takagi
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003465:Culex / Q000821:virology*; D004664:Encephalitis Virus, Japanese / Q000145:classification* / Q000302:isolation & purification / Q000472:pathogenicity; D004672:Encephalitis, Japanese / Q000821:virology; D005814:Genes, Viral; D014644:Genetic Variation; D005838:Genotype; D007303:Insect Vectors / Q000821:virology*; D008562:Membrane Glycoproteins / Q000032:analysis / Q000235:genetics; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014744:Vietnam; D014759:Viral Envelope Proteins / Q000032:analysis / Q000235:genetics
D008562:Membrane Glycoproteins; D012367:RNA, Viral; D014759:Viral Envelope Proteins; C080628:glycoprotein E, Japanese encephalitis virus