Incidence and risk factors for urethral and anal gonorrhoea and chlamydia in a cohort of HIV-negative homosexual men: the Health in Men Study
- F Jin1,
- G P Prestage1,
- L Mao2,
- S C Kippax2,
- C M Pell3,
- B Donovan1,
- P H Cunningham4,
- D J Templeton1,
- J M Kaldor1,
- A E Grulich1
- 1National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, New South Wales, Australia
- 2National Centre in HIV Social Research, University of New South Wales, Sydney, New South Wales, Australia
- 3Taylor Square Private Clinic, Darlinghurst, Australia
- 4Centre for Immunology, St Vincent’s Hospital, Sydney, New South Wales, Australia
- Correspondence to: Fengyi Jin National Centre in HIV Epidemiology and Clinical Research, Level 2, 376 Victoria Street, Darlinghurst, NSW 2010, Australia;
- Accepted 26 September 2006
- Published Online First 27 September 2006
Background: Early detection and treatment of bacterial sexually transmitted infections has been advocated as an HIV prevention strategy.
Aim: To inform screening guidelines, the incidence and risk factors for urethral and anal gonorrhoea and chlamydia were studied in a prospective cohort of community-based HIV negative homosexual men in Sydney, New South Wales, Australia.
Methods: All participants were offered annual screening for gonorrhoea and chlamydia (study-visit diagnoses) on urine and anal swabs using nucleic acid amplification. Participants also reported diagnoses of gonorrhoea and chlamydia made elsewhere between interviews (interval diagnoses). All diagnoses were summed to create a combined incidence rate, and detailed data on specific sexual practices with casual and regular partners were collected.
Results: Among 1427 men enrolled, the combined incidence rates were 3.49 and 2.96 per 100 person-years for urethral and anal gonorrhoea, respectively; and 7.43 and 4.98 per 100 person-years for urethral and anal chlamydia, respectively. Urethral infections were associated with unprotected anal intercourse (UAI) with HIV-positive partners (hazard ratio (HR) = 2.58, 95% CI 1.10 to 6.05 for urethral gonorrhoea) and with frequent insertive oral sex (p for trend 0.007 for urethral chlamydia). Anal infections were associated with receptive UAI (p for trend 0.001 for both anal gonorrhoea and chlamydia) and other receptive anal sexual practices. Stratified analyses showed the independence of the associations of insertive oral sex with urethral infections and of non-intercourse receptive anal practices with anal infections.
Conclusion: Incident gonorrhoea and chlamydia were common. Risk behaviours for both urethral and anal infections were not restricted to UAI. Screening that includes tests for anal and urethral infections should be considered for all sexually active homosexual men, not just for those who report UAI.
- HIM, Health in Men
- NAAT, nucleic acid amplification testing
- SDA, strand displacement amplification
- STI, sexually transmitted infection
- UAI, unprotected anal intercourse
Published Online First 27 September 2006
Funding: The National Centre in HIV Epidemiology and Clinical Research and the National Centre in HIV Social Research are funded by the Australian Government Department of Health and Ageing. The Health in Men cohort study was funded by the National Institutes of Health, a component of the US Department of Health and Human Services (NIH/NIAID/DAIDS: HVDDT Award N01-AI-05395), the National Health and Medical Research Council in Australia (project grant number 400944), the Australian Government Department of Health and Ageing, Canberra and the New South Wales Health Department, Sydney.
Competing interests: None.
Contributors: FJ carried out the analyses and drafted the manuscript. AEG was overall responsible for the project and assisted in the analyses and drafting of the manuscript. GPP, LM, SCK, BD, CMP, DJT, PHC and JMK assisted in formulating the analyses and drafting the manuscript. BD, CMP and DJT assisted with interpretation of the clinical aspect of the infections. PHC assisted with interpretation of the test results.