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Prevalence, incidence and predictors of anal Chlamydia trachomatis, anal Neisseria gonorrhoeae and syphilis among older gay and bisexual men in the longitudinal Study for the Prevention of Anal Cancer (SPANC)
  1. Sian Louise Goddard1,2,
  2. Isobel M Poynten1,
  3. Kathy Petoumenous3,
  4. Fengyi Jin1,
  5. Richard J Hillman4,
  6. Carmella Law4,
  7. Jennifer M Roberts5,
  8. Christopher K Fairley6,7,
  9. Suzanne M Garland8,9,10,
  10. Andrew E Grulich1,
  11. David J Templeton1,11
  12. on behalf of the Study for the Prevention of Anal Cancer (SPANC) Research Team
  1. 1 HIV Epidemiology and Prevention Program, The Kirby Institute, Sydney, New South Wales, Australia
  2. 2 Ambrose King Centre, Barts Health NHS Trust, London, UK
  3. 3 Biostatistics and Databases Program, The Kirby Institute, Sydney, New South Wales, Australia
  4. 4 HIV, Immunology and Infectious disease Department, St Vincent’s Hospital, Sydney, New South Wales, Australia
  5. 5 Cytology Department, Douglas Hanly Moir Pathology, Sydney, New South Wales, Australia
  6. 6 Central Clinical School, Monash University, Melbourne, Victoria, Australia
  7. 7 Melbourne Sexual Health Centre, Melbourne, Victoria, Australia
  8. 8 Centre for Women’s Infectious Diseases, The Royal Women’s Hospital, Melbourne, Victoria, Australia
  9. 9 Infection Immunity, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
  10. 10 Department of Obstetrics and Gynaecology, University of Melbourne, Parkville, Victoria, Australia
  11. 11 Sexual Health Service, Sydney Local Health District, Camperdown, New South Wales, Australia
  1. Correspondence to Dr Sian Louise Goddard, The Kirby Institute, Sydney, NSW 2052, Australia; sgoddard{at}


Objectives Sexually transmitted infection (STI) notifications are increasing among older individuals. Many older gay and bisexual men (GBM) are sexually active and have multiple partners. We aimed to investigate the prevalence, incidence and predictors of anal chlamydia, anal gonorrhoea and syphilis in older GBM.

Methods The Study for the Prevention of Anal Cancer (SPANC) was a prospective cohort study of HPV infections and related anal lesions among community-recruited GBM age ≥ 35 years in Sydney, Australia. At baseline and subsequent annual visits, recent STI diagnoses were collected via questionnaire (‘interval diagnoses’) and STI testing occurred (‘study visit diagnoses’). Baseline STI prevalence was calculated using study visit diagnoses. Incidence of anal chlamydia and gonorrhoea was calculated using interval and study visit diagnoses. Syphilis incidence was calculated using interval diagnoses. Univariate and multivariate analysis using Cox proportional hazards were undertaken to investigate the association between risk factors and incident STI.

Results Among 617 GBM, the median age was 49 years (range 35–79) and 35.8% (n=221) were HIV-positive. At baseline, STI prevalence was: anal chlamydia 2.3% (n=14); anal gonorrhoea 0.5% (n=3) and syphilis 1.0% (n=6). During 1428 person-years of follow-up (PYFU), the incidence (per 100 PYFU) of anal chlamydia, anal gonorrhoea and syphilis was 10.40 (95% CI 8.82 to 12.25), 9.11 (95% CI 7.64 to 10.85) and 5.47 (95% CI 4.38 to 6.84), respectively. In multivariate analysis, HIV-positivity, higher number of recent condomless receptive anal intercourse partners and baseline methamphetamine use were associated with each STI. Sex with ‘fuck-buddies’ was associated with anal chlamydia and gonorrhoea. Age was not associated with any STI.

Discussion There was a high incidence of STI among SPANC participants. Age should not be used as a proxy for sexual risk and older GBM require a detailed sexual behaviour and recreational drug use history. Interventions that specifically target STI risk among older GBM should be considered.

  • chlamydia trachomatis
  • neisseria gonorrhoea
  • syphilis
  • sexual behaviour
  • gay men

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  • Handling editor Khalil G Ghanem

  • Collaborators In addition to the co-authors of this manuscript, the SPANC study team includes:

    Annabelle Farnsworth, Clare Biro, Adele Richards, Julia Thurloe, Deborah Ekman, Ross McDonald, Marjorie Adams, Sepehr Tabrizi, Alyssa Cornall, Samuel Phillips, Monica Molano Luque, Simon Comben, Kirsten McCaffery, Kirsten Howard, Patrick Kelly, Daniel Seeds, Andrew Carr, Lance Feeney, Russ Gluyas, Garrett Prestage, Matthew Law, Brian Acraman, Patrick McGrath, Robert Mellor, Piero Pezzopane, Rick Varma, Julian Langton-Lockton and Winnie Tong.

  • Contributors SLG (PhD student) contributed to the study design, performed the data analysis and drafted the manuscript. DJT and IMP conceived of the study, participated in its design, analysis and interpretation of data and reviewed the manuscript. KP assisted with study design, statistical analysis and manuscript review. FJ assisted with data analysis and reviewed the manuscript. CL retrospectively reviewed the medical records of participants to confirm baseline prevalent syphilis diagnoses. All other authors reviewed and contributed to the manuscript.

  • Funding The SPANC study was funded by a National Health and Medical Research Council Program Grant (Sexually transmitted infections: Causes, consequences and interventions Grant #568971); and a Cancer Council New South Wales Strategic Research Partnership Program Grant (preventing morbidity and mortality from anal cancer grant #13-11). Cytological testing materials were provided by Hologic Pty Ltd. The Kirby Institute is affiliated with the Faculty of Medicine, University of New South Wales, and funded by the Australian Government of Health and Ageing.

  • Competing interests AEG has received honoraria and research funding from CSL Biotherapies, honoraria and travel funding from Merck. CKF has received honoraria, travel funding and research funding from CSL and Merck, and owns shares in CSL Biotherapies. SMG has received advisory board fees and grant support from CSL and GlaxoSmithKline, and lecture fees from Merck, GlaxoSmithKline and Sanofi Pasteur; in addition, has received funding through her institution to conduct clinical HPV vaccine studies for MSD and GlaxoSmithKline and is a member of the Merck Global Advisory Board as well as the Merck Scientific Advisory Committee for HPV. RJH has received support from CSL Biotherapies and MSD.

  • Patient consent for publication Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available on reasonable request.