title: Evidence of an explosive epidemic of HIV infection in a cohort of men who have sex with men in Thailand.
abstract: OBJECTIVE
  To assess HIV-prevalence, incidence and risk factors in a cohort of men who have sex with men (MSM) in Bangkok.
  
  
  METHODS
  : Cohort study with 4-monthly follow-up visits conducted between April 2006 and July 2012 at a dedicated study clinic in a central Bangkok hospital. Participants were 1744 homosexually active Thai men, at least 18 years old and residents of Bangkok.
  
  
  METHODS
  Men were tested for HIV-infection at every study visit and for sexually transmitted infections at baseline. Demographic and behavioural data were collected by audio-computer-assisted self-interview. Logistic regression analysis was used to evaluate risk factors for HIV-prevalence and Cox proportional hazard analysis to evaluate risk factors for HIV-incidence.
  
  
  RESULTS
  Baseline HIV-prevalence was 21.3% (n = 372) and 60 months cumulative HIV-incidence was 23.9% (n = 222). Overall HIV-incidence density was 5.9 per 100 person-years. Multivariate risk factors for HIV-prevalence were older age, secondary/vocational education (vs. university or higher), employed or unemployed (vs. studying), nitrate inhalation, drug use for sexual pleasure, receptive anal intercourse, history of sexual coercion, no prior HIV-testing, and anti-HSV-1 and 2 and Treponema pallidum positivity at baseline. Multivariate risk factors for HIV-incidence were younger age, living alone or with roommate (vs. with a partner or family), drug use for sexual pleasure, inconsistent condom use, receptive anal intercourse, group sex, and anti-HSV-1 and 2 and T. pallidum positivity at baseline. Having no anal intercourse partners was inversely associated with HIV-incidence.
  
  
  CONCLUSIONS
  The high HIV prevalence and incidence in this cohort of Bangkok MSM documents an explosive epidemic. Additional preventive interventions for MSM are urgently needed.
authors.affiliation: Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA. fritsvg@trcarc.org
authors.forename: Frits
authors.initials: F
authors.lastname: van Griensven
authors.forename: Warunee
authors.initials: W
authors.lastname: Thienkrua
authors.forename: Janet
authors.initials: J
authors.lastname: McNicholl
authors.forename: Wipas
authors.initials: W
authors.lastname: Wimonsate
authors.forename: Supaporn
authors.initials: S
authors.lastname: Chaikummao
authors.forename: Wannee
authors.initials: W
authors.lastname: Chonwattana
authors.forename: Anchalee
authors.initials: A
authors.lastname: Varangrat
authors.forename: Pachara
authors.initials: P
authors.lastname: Sirivongrangson
authors.forename: Philip A
authors.initials: PA
authors.lastname: Mock
authors.forename: Pasakorn
authors.initials: P
authors.lastname: Akarasewi
authors.forename: Jordan W
authors.initials: JW
authors.lastname: Tappero
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D015658:HIV Infections / Q000453:epidemiology*; D018451:Homosexuality, Male / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012747:Sexual Partners; D013785:Thailand / Q000453:epidemiology; D055815:Young Adult