title: HCV Diversity among Chinese and Burmese IDUs in Dehong, Yunnan, China.
abstract: HCV transmission is closely associated with drug-trafficking routes in China. Dehong, a prefecture of Yunnan, is the important trade transfer station linking Southeast Asia and China, as well as the drug-trafficking channel linking "Golden triangle" and other regions of China and surrounding countries. In this study, we investigated the HCV genotype diversity among IDUs in Dehong based on 259 HCV positive samples from 118 Chinese and 141 Burmese IDUs. HCV genotypes were determined based on the phylogenies of C/E2 and NS5B genomic sequences. Six HCV subtypes, including 1a, 1b, 3a, 3b, 6n and 6u, were detected. Interestingly, 4 HCV sequences from Burmese IDUs did not cluster with any known HCV subtypes, but formed a well-supported independent clade in the phylogenetic trees of both C/E2 and NS5B, suggesting a potential new HCV subtype circulating in Dehong. Subtype 3b was the predominant subtype, followed by subtypes 6n and 6u. Comparison showed that Dehong had a unique pattern of HCV subtype distribution, obviously different from other regions of China. In particular, HCV subtypes 6u and the potential new HCV subtype had a relatively high prevalence in Dehong, but were rarely detected in other regions of China. There was no significant difference in HCV subtype distribution between Burmese and Chinese IDUs. Few HCV sequences from Burmese and Chinese IDUs clustered together to form transmission clusters. Furthermore, about half of HCV sequences from Burmese IDUs formed small transmission clusters, significantly higher than that from Chinese IDUs (p<0.01). These suggest that the Chinese and Burmese IDUs were relatively isolated from each other in injection drug use behavior and the Burmese IDUs might prefer to inject drugs themselves together. The unique genotype distribution and complex diversity of genotype 6 among IDUs may be associated with the special geographical position of Dehong.
authors.affiliation: Pathogen Diagnostic Center, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200031, China.|Medical Laboratory of Taizhou Fourth People's Hospital, Taizhou, Jiangsu 225300, China.
authors.forename: Zhenzhou
authors.initials: Z
authors.lastname: Wan
authors.affiliation: Pathogen Diagnostic Center, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.|Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan 650204, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.affiliation: The Second People's Hospital of Yunnan Province, Kunming, Yunnan 650031, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Duo
authors.affiliation: Pathogen Diagnostic Center, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Peilu
authors.initials: P
authors.lastname: Li
authors.affiliation: Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.
authors.forename: Yong-Tang
authors.initials: YT
authors.lastname: Zheng
authors.affiliation: Pathogen Diagnostic Center, CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Chiyu
authors.initials: C
authors.lastname: Zhang