title: High prevalence of HIV, chlamydia and gonorrhoea among men who have sex with men and transgender women attending trusted community centres in Abuja and Lagos, Nigeria.
abstract: Sexually transmitted infection (STI) and HIV prevalence have been reported to be higher amongst men who have sex with men (MSM) in Nigeria than in the general population. The objective of this study was to characterize the prevalence of HIV, chlamydia and gonorrhoea in this population using laboratory-based universal testing.
  
  
  
  TRUST/RV368 represents a cohort of MSM and transgender women (TGW) recruited at trusted community centres in Abuja and Lagos, Nigeria, using respondent-driven sampling (RDS). Participants undergo a structured comprehensive assessment of HIV-related risks and screening for anorectal and urogenitalChlamydia trachomatisandNeisseria gonorrhoeae, and HIV. Crude and RDS-weighted prevalence estimates with 95% confidence intervals (CIs) were calculated. Log-binomial regression was used to explore factors associated with prevalent HIV infection and STIs.
  
  
  
  From March 2013 to January 2016, 862 MSM and TGW (316 in Lagos and 546 in Abuja) underwent screening for HIV, chlamydia and gonorrhoea at study enrolment. Participants' median age was 24 years [interquartile range (IQR) 21-27]. One-third (34.2%) were identified as gay/homosexual and 65.2% as bisexual. The overall prevalence of HIV was 54.9%. After adjusting for the RDS recruitment method, HIV prevalence in Abuja was 43.5% (95% CI 37.3-49.6%) and in Lagos was 65.6% (95% CI 54.7-76.5%). The RDS-weighted prevalence of chlamydia was 17.0% (95% CI 11.8-22.3%) in Abuja and 18.3% (95% CI 11.1-25.4%) in Lagos. Chlamydia infection was detected only at the anorectal site in 70.2% of cases. The RDS-weighted prevalence of gonorrhoea was 19.1% (95% CI 14.6-23.5%) in Abuja and 25.8% (95% CI 17.1-34.6%) in Lagos. Overall, 84.2% of gonorrhoea cases presented with anorectal infection only. Over 95% of STI cases were asymptomatic. In a multivariable model, increased risk for chlamydia/gonorrhoea was associated with younger age, gay/homosexual sexual orientation and higher number of partners for receptive anal sex. HIV infection was associated with older age, female gender identity and number of partners for receptive anal sex.
  
  
  
  There is a high burden of infection with HIV and asymptomatic chlamydia and gonorrhoea among MSM and TGW in Nigeria. Most cases would have been missed without anorectal screening. Interventions are needed to target this population for appropriate STI screening and management beginning at a young age.
authors.affiliation: Department of Defense Walter Reed Program-Nigeria, Abuja, Nigeria; ibkesh@gmail.com.
authors.forename: Babajide
authors.initials: B
authors.lastname: Keshinro
authors.affiliation: Walter Reed Army Institute of Research, U.S. Military HIV Research Program, Silver Spring, MD, USA.|Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA.
authors.forename: Trevor A
authors.initials: TA
authors.lastname: Crowell
authors.affiliation: Institute of Human Virology, University of Maryland, Baltimore, MD, USA.
authors.forename: Rebecca G
authors.initials: RG
authors.lastname: Nowak
authors.affiliation: Population Council Nigeria, Abuja, Nigeria.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Adebajo
authors.affiliation: Walter Reed Army Institute of Research, U.S. Military HIV Research Program, Silver Spring, MD, USA.
authors.forename: Sheila
authors.initials: S
authors.lastname: Peel
authors.affiliation: Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Charlotte A
authors.initials: CA
authors.lastname: Gaydos
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
authors.forename: Cristina
authors.initials: C
authors.lastname: Rodriguez-Hart
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
authors.forename: Stefan D
authors.initials: SD
authors.lastname: Baral
authors.affiliation: Walter Reed Army Institute of Research, U.S. Military HIV Research Program, Silver Spring, MD, USA.|Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA.
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Walsh
authors.affiliation: Department of Defense Walter Reed Program-Nigeria, Abuja, Nigeria.
authors.forename: Ogbonnaya S
authors.initials: OS
authors.lastname: Njoku
authors.affiliation: Department of Defense Walter Reed Program-Nigeria, Abuja, Nigeria.
authors.forename: Sunday
authors.initials: S
authors.lastname: Odeyemi
authors.affiliation: Institute of Human Virology Nigeria, Abuja, Nigeria.
authors.forename: Teclaire
authors.initials: T
authors.lastname: Ngo-Ndomb
authors.affiliation: Institute of Human Virology, University of Maryland, Baltimore, MD, USA.
authors.forename: William A
authors.initials: WA
authors.lastname: Blattner
authors.affiliation: Walter Reed Army Institute of Research, U.S. Military HIV Research Program, Silver Spring, MD, USA.|Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA.
authors.forename: Merlin L
authors.initials: ML
authors.lastname: Robb
authors.affiliation: Institute of Human Virology, University of Maryland, Baltimore, MD, USA.
authors.forename: Manhattan E
authors.initials: ME
authors.lastname: Charurat
authors.affiliation: Walter Reed Army Institute of Research, U.S. Military HIV Research Program, Silver Spring, MD, USA.
authors.forename: Julie
authors.initials: J
authors.lastname: Ake
mesh_terms: D000293:Adolescent; D000328:Adult; D002690:Chlamydia Infections / Q000453:epidemiology*; D002692:Chlamydia trachomatis; D005260:Female; D006069:Gonorrhea / Q000453:epidemiology*; D015658:HIV Infections / Q000453:epidemiology*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D009344:Neisseria gonorrhoeae; D009549:Nigeria / Q000453:epidemiology; D015995:Prevalence; D012111:Residence Characteristics; D012725:Sexual Behavior; D012747:Sexual Partners; D012749:Sexually Transmitted Diseases / Q000453:epidemiology; D011795:Surveys and Questionnaires; D063106:Transgender Persons; D055815:Young Adult
keywords: HIV; MSM; Nigeria; chlamydia; gonorrhoea; prevalence