title: Diverse origins of hepatitis C virus in HIV co-infected men who have sex with men in Hong Kong.
abstract: BACKGROUND
  Worldwide, Hepatitis C (HCV) infection has been increasingly recognized in HIV-positive men who have sex with men (MSM). The objective of this study was to characterize the transmission dynamics of acute HCV infection in HIV-positive MSM in Hong Kong using a molecular approach.
  
  
  RESULTS
  We retrospectively examined 24 HIV-positive MSM with acute HCV infection diagnosed between 2009 and 2014 in Hong Kong. Detection and molecular characterization of HCV was successfully performed in 22 (91.7 %) patients. Genotype 3a was the most prevalent as identified in 14 (63.6 %) MSM, followed by 1a in 4 (18.2 %), 6a in 2 (9.1 %), and 1each (4.5 %) for 1b and 2a. The high prevalence of genotype 3a in MSM was in stark contrast to its rarity among HCV infected injection drug users (IDU) in Hong Kong. Phylogenetic analyses revealed a monophyletic HCV-3a cluster composing of MSM without injection history, and a homologous pair with HCV-6a genotype. There was otherwise no temporal or genetic clustering of the corresponding HIV sequences.
  
  
  CONCLUSIONS
  The origin of sexually acquired acute HCV infections in HIV-positive MSM was diverse and not directly linked with local IDU. The transmission dynamics of HIV and HCV infections in MSM in Hong Kong were evidently unrelated.
authors.affiliation: Stanley Ho Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Hong Kong, China. denisechan@cuhk.edu.hk.
authors.forename: Denise P
authors.initials: DP
authors.lastname: Chan
authors.affiliation: Centre for Health Protection, Department of Health, Hong Kong, China. adalinwc@dh.gov.hk.
authors.forename: Ada W
authors.initials: AW
authors.lastname: Lin
authors.affiliation: Centre for Health Protection, Department of Health, Hong Kong, China. khwong@dh.gov.hk.
authors.forename: Ka Hing
authors.initials: KH
authors.lastname: Wong
authors.affiliation: Stanley Ho Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Hong Kong, China. isswong@gmail.com.
authors.forename: Ngai Sze
authors.initials: NS
authors.lastname: Wong
authors.affiliation: Stanley Ho Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Hong Kong, China. sslee@cuhk.edu.hk.
authors.forename: Shui Shan
authors.initials: SS
authors.lastname: Lee
mesh_terms: D000328:Adult; D060085:Coinfection; D005838:Genotype; D015658:HIV Infections / Q000453:epidemiology*; D015497:HIV-1; D016174:Hepacivirus / Q000145:classification / Q000235:genetics*; D006526:Hepatitis C / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology; D018451:Homosexuality, Male; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D010802:Phylogeny; D017361:Viral Nonstructural Proteins / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase
chemical_list: D017361:Viral Nonstructural Proteins; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase