title: Sequence variation of dengue type 2 virus isolated from clinical cases in Thailand.
abstract: Dengue fever (DF) and dengue hemorrhagic fever (DHF) are caused by mosquito-borne dengue virus (DENV) infection leading to death in tropical and subtropical countries. In Thailand, all 4 serotypes of DENV are circulating. The most severe cases of DF and DHF are primarily introduced by secondary infections. Epidemiological studies have demonstrated that approximately 20% of the primary infection cases were caused by DENV-1 and -3, while the cases of DENV-2 or -4 accounted for less than 3%. For this reason, DENV-2 and -4 from primary infections have not been well studied. In this study, the sequence diversity of the envelope gene of 8 DENV-2 clinical isolates from primary/secondary infections was analyzed. DENV-2 from primary infections were highly heterogeneous in individual patients, whereas those from secondary infections were homogeneous. Phylogenetic analysis demonstrated that the heterogeneous population of DENV-2 from primary infections was composed of closely related quasispecies. Homogenous DENV-2 could be derived from selection of a particular viral population in secondary infections. The degree of sequence diversity of DENV-2 varied, and thus quasispecies may be involved in the progression of DENV infection.
authors.affiliation: Research Collaboration Center on Emerging and Re-emerging Infections (RCC-ERI), Research Institute for Microbial Diseases (RIMD), Osaka University.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kurosu
authors.forename: Panjaporn
authors.initials: P
authors.lastname: Chaichana
authors.forename: Supranee
authors.initials: S
authors.lastname: Phanthanawiboon
authors.forename: Chidchanok
authors.initials: C
authors.lastname: Khamlert
authors.forename: Akifumi
authors.initials: A
authors.lastname: Yamashita
authors.forename: Atchareeya
authors.initials: A
authors.lastname: A-nuegoonpipat
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Ikuta
authors.forename: Surapee
authors.initials: S
authors.lastname: Anantapreecha
mesh_terms: D016000:Cluster Analysis; D003715:Dengue / Q000821:virology*; D003716:Dengue Virus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013785:Thailand; D014759:Viral Envelope Proteins / Q000235:genetics
chemical_list: D012367:RNA, Viral; D014759:Viral Envelope Proteins