title: [HIV-1 subtype diversity and transmission clusters among men having sex with men who recently got HIV-l infection, in Zhejiang province].
abstract: OBJECTIVE
  To understand the HIV-1 subtype diversity and transmission characteristics in men having sex with men (MSM) in Zhejiang province.
  
  
  METHODS
  A total of 233 newly diagnosed as HIV-1 positive patients in 2011 were screened out by BED capture enzyme immunoassay (BED-CEIA). Among them, 107 eligible subjects were enrolled for further molecular epidemiological study. Viral RNA was extracted from plasma samples and followed by reverse transcription PCR and nested PCR for amplification of pol gene fragments, sequencing, and bioinformatics analysis.
  
  
  RESULTS
  There were no statistically significant differences regarding the social demographic distribution between the subjects under study and those recently infected MSM population. The rate of success for sequence acquisition was 94.4% (101/107). The highest proportion of subtype was CRF01_AE (62.4%), followed by CRF07_BC (31.7%) and with three cases of subtype B, one case of CRF55_01B and two cases of unique recombinant form (CRF01_AE/B and CRF01_AE/CRF07_BC). The phylogenetic trees were mainly divided into CRF01_AE cluster 1, cluster 2 and CRF07_BC cluster 3. The strains located in Hangzhou were diffused in the branches of phylogenetic tree. 10 transmission clusters were found, in which 80% involved two or more regions and 90% was associated with patients residing in Hangzhou. Three surveillance drug resistance mutations (M46I, T215S and G190A) were found in three samples (each sample harbored only one resistance mutation). The overall rate of transmitted drug resistance (TDR) was 2.97%.
  
  
  CONCLUSIONS
  The increasing complexity of HIV was noticed in MSM in Zhejiang province. However, the prevalence of TDR was low. Cross-regional HIV transmission in MSM was common, which inferred from the study. Hangzhou might play a central regional role in the intra-provincial spread of HIV, to form an interwoven complex network in the MSM population.
authors: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China.
authors: Jiafeng
authors: J
authors: Zhang
authors: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China.
authors: Jiezhe
authors: J
authors: Yang
authors: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China. Email: xhpan@cdc.zj.cn.
authors: Xiaohong
authors: X
authors: Pan
authors: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China.
authors: Zhihong
authors: Z
authors: Guo
authors: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China.
authors: Xiaobei
authors: X
authors: Ding
authors: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China.
authors: Yun
authors: Y
authors: Xu
authors: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China.
authors: Jingjing
authors: J
authors: Huang
authors: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China.
authors: Yan
authors: Y
authors: Xia
mesh_terms: D002681:China / Q000453:epidemiology; D003710:Demography; D024882:Drug Resistance, Viral; D015751:Genes, pol; D015658:HIV Infections / Q000235:genetics / Q000635:transmission*; D015497:HIV-1 / Q000145:classification*; D006716:Homosexuality; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D010802:Phylogeny; D015995:Prevalence; D012367:RNA, Viral
chemical_list: D012367:RNA, Viral