title: Serosorting and recreational drug use are risk factors for diagnosis of genital infection with chlamydia and gonorrhoea among HIV-positive men who have sex with men: results from a clinical cohort in Ontario, Canada.
abstract: OBJECTIVE
  Rates of chlamydia and gonorrhoea have been rising in urban centres in Canada, particularly among HIV-positive men who have sex with men (MSM). Our objective was to identify behavioural risk factors for diagnosis with chlamydia and gonorrhoea in this population, with a focus on the HIV status of sexual partners.
  
  
  METHODS
  The OHTN Cohort Study follows people in HIV care across Ontario. We restricted the analysis to 1997 MSM who completed questionnaires in 2010-2013 at one of seven clinics that submit all chlamydia and gonorrhoea tests to the provincial public health laboratory; we obtained test results via record linkage. We estimated cumulative incidences using Kaplan-Meier methods and identified risk factors for diagnosis of a composite outcome (chlamydia or gonorrhoea infection) using Cox regression.
  
  
  RESULTS
  At follow-up, there were 74 new chlamydia/gonorrhoea diagnoses with a 12-month cumulative incidence of 1.7% (95% CI 1.1% to 2.2%). Risk factors for chlamydia/gonorrhoea diagnosis were: 5+ HIV-positive partners (HR=3.3, 95% CI 1.4 to 7.8; reference=none) and recreational drug use (HR=2.2, 95% CI 1.2 to 3.9).
  
  
  CONCLUSIONS
  Heightened risks with recreational drug use and multiple HIV-positive partners suggest that chlamydia/gonorrhoea may have achieved high prevalence in certain sexual networks among HIV-positive MSM. Interventions to promote safer sex and timely testing among MSM are needed.
authors.affiliation: Centre for Research on Inner City Health, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Ramandip
authors.initials: R
authors.lastname: Grewal
authors.affiliation: Public Health Laboratories, Public Health Ontario, Toronto, Ontario, Canada.
authors.forename: Vanessa G
authors.initials: VG
authors.lastname: Allen
authors.affiliation: Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.|Baycrest Health Science, Toronto, Ontario, Canada.
authors.forename: Sandra
authors.initials: S
authors.lastname: Gardner
authors.affiliation: Ontario HIV Treatment Network, Toronto, Ontario, Canada.
authors.forename: Veronika
authors.initials: V
authors.lastname: Moravan
authors.affiliation: Department of Medicine, University of Toronto, Toronto, Ontario, Canada.|Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada.|Division of Infectious Diseases, St. Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Darrell H S
authors.identifier: http://orcid.org/0000-0002-3069-2875
authors.initials: DH
authors.lastname: Tan
authors.affiliation: Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.|Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada.
authors.forename: Janet
authors.initials: J
authors.lastname: Raboud
authors.affiliation: Centre for Research on Inner City Health, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.|Department of Medicine, University of Toronto, Toronto, Ontario, Canada.|Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada.|Division of Infectious Diseases, St. Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Bayoumi
authors.affiliation: Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Rupert
authors.initials: R
authors.lastname: Kaul
authors.affiliation: Public Health Laboratories, Public Health Ontario, Toronto, Ontario, Canada.|Department of Microbiology, Mount Sinai Hospital/University Health Network, Toronto, Ontario, Canada.
authors.forename: Tony
authors.initials: T
authors.lastname: Mazzulli
authors.affiliation: AIDS Bureau, Ontario Ministry of Health and Long-Term Care, Toronto, Ontario, Canada.
authors.forename: Frank
authors.initials: F
authors.lastname: McGee
authors.affiliation: Centre for Research on Inner City Health, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.|Ontario HIV Treatment Network, Toronto, Ontario, Canada.|Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Sean B
authors.initials: SB
authors.lastname: Rourke
authors.affiliation: Centre for Research on Inner City Health, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.|Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.|Department of Family and Community Medicine, St. Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Ann N
authors.initials: AN
authors.lastname: Burchell
mesh_terms: D002690:Chlamydia Infections / Q000175:diagnosis* / Q000453:epidemiology*; D006069:Gonorrhea / Q000175:diagnosis* / Q000453:epidemiology*; D015658:HIV Infections / Q000097:blood / Q000150:complications* / Q000453:epidemiology; D059147:HIV Serosorting / Q000187:drug effects / Q000523:psychology / Q000706:statistics & numerical data*; D018451:Homosexuality, Male / Q000706:statistics & numerical data*; D006801:Humans; D013287:Illicit Drugs; D008297:Male; D009864:Ontario / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D019966:Substance-Related Disorders / Q000453:epidemiology*
chemical_list: D013287:Illicit Drugs
keywords: CHLAMYDIA INFECTION; GAY MEN; GONORRHOEA; HIV; SEXUAL BEHAVIOUR