title: Epidemiology of HIV-1 subtypes among men who have sex with men in Cape Town, South Africa.
abstract: OBJECTIVE
  Early studies in Cape Town identified independent HIV-1 epidemics, with distinct viral subtypes, among men who have sex with men (MSM) and the heterosexual population. However, few recent HIV-1 subtype data are available for MSM in South Africa. We examined HIV-1 subtypes among MSM in Cape Town.
  
  
  METHODS
  Cross-sectional survey.
  
  
  METHODS
  Self-identified MSM were recruited from geographically and racially disparate communities across Cape Town. Participants completed behavioral questionnaires and underwent HIV testing. Virus isolated from infected participants underwent complete env gp160 sequencing, and HIV-1 subtypes were assigned through phylogenetic analysis.
  
  
  RESULTS
  In total, 194 HIV-infected MSM were enrolled: 67% black African, 24% colored, and 9% white men. More black African men identified as bisexual or heterosexual compared with other races. Overall, 31%-66% of men reported a recent partner of another race. HIV-1 subtypes were confirmed for 143 participants: 81% were subtype C, 14% B, 1% A1, 1% F2, and 3 recombinant viruses. Subtype C virus was associated with black African race (P = 0.003 compared with colored; P < 0.001 compared with white), men who identified as bisexual/heterosexual (P = 0.01), and reported a female sexual partner in the last year (P = 0.02). Compared with previous studies, an increasing prevalence of subtype C virus was noted among white MSM.
  
  
  CONCLUSIONS
  This molecular epidemiology study provides novel evidence of sexual network links between the heterosexual and MSM epidemics and between historically racially disparate communities. These findings provide insights into the drivers of HIV epidemics in different population groups and may have implications for prevention strategies.
authors.affiliation: *Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine and †Department of Medicine, University of Cape Town, Cape Town, South Africa; ‡Division of Medical Virology and §Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa; ‖Division of Epidemiology & Biostatistics, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa; ¶Center for Learning and Innovation, San Francisco Department of Public Health, San Francisco, CA; #University of California, San Francisco; and **National Health Laboratory Services, Cape Town, South Africa.
authors.forename: Keren
authors.initials: K
authors.lastname: Middelkoop
authors.forename: Cecilia
authors.initials: C
authors.lastname: Rademeyer
authors.forename: Ben B
authors.initials: BB
authors.lastname: Brown
authors.forename: Tamaryn J
authors.initials: TJ
authors.lastname: Cashmore
authors.forename: Jinny C
authors.initials: JC
authors.lastname: Marais
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Scheibe
authors.forename: Gama P
authors.initials: GP
authors.lastname: Bandawe
authors.forename: Landon
authors.initials: L
authors.lastname: Myer
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Fuchs
authors.forename: Carolyn
authors.initials: C
authors.lastname: Williamson
authors.forename: Linda-Gail
authors.initials: LG
authors.lastname: Bekker
mesh_terms: D000328:Adult; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D005260:Female; D005838:Genotype; D019302:HIV Envelope Protein gp160 / Q000235:genetics; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013019:South Africa; D011795:Surveys and Questionnaires
chemical_list: D019302:HIV Envelope Protein gp160