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Comparison of the patterns of chlamydia and gonorrhoea at the oropharynx, anorectum and urethra among men who have sex with men
  1. Marjan Tabesh1,2,
  2. Christopher K Fairley1,2,
  3. Jane S Hocking3,
  4. Deborah A Williamson4,5,
  5. Lei Zhang1,2,6,
  6. Xianglong Xu1,2,7,
  7. Catriona S Bradshaw1,2,
  8. Marcus Y Chen1,2,
  9. Eric PF Chow1,2,3
  1. 1 Melbourne Sexual Health Centre, Alfred Health, Melbourne, Victoria, Australia
  2. 2 Central Clinical School, Monash University, Melbourne, Victoria, Australia
  3. 3 Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
  4. 4 Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity at The University of Melbourne, Melbourne, Victoria, Australia
  5. 5 Department of Microbiology, Royal Melbourne Hospital, Melbourne, Victoria, Australia
  6. 6 Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, China
  7. 7 China Australia Joint Research Center for Infectious Diseases, School of Public Health, Xi'an Jiaotong University Health Science Centre, Xi'an, Shanxi, China
  1. Correspondence to Associate Professor Eric PF Chow, Central Clinical School, Monash University, Melbourne, Victoria, Australia; eric.chow{at}


Objective Chlamydia and gonorrhoea are common sexually transmitted infections that infect the oropharynx, anorectum and urethra in men who have sex with men (MSM). This study aimed to examine the pattern of infection at more than one site (multisite) for chlamydia and gonorrhoea among MSM.

Methods This was a retrospective study of MSM attending the Melbourne Sexual Health Centre for the first time between 2018 and 2019. We included MSM aged ≥16 years who had tested for Neisseria gonorrhoeae and Chlamydia trachomatis at all three sites (oropharynx, anorectum and urethra). We compared infections that occurred at a single site (termed single-site infection) and those that occurred at more than one site (termed multisite infections).

Results Of the 3938 men who were tested for chlamydia and gonorrhoea, 498/3938 men (12.6%, 95% CI 11.5% to 13.6%) had chlamydia at any site, of whom 400/498 (80.3%, 95% CI 78.9% to 81.2%) had single-site chlamydia infection, and 98/498 (19.7%, 95% CI 16.2% to 23.1%) had multisite infections. A similar proportion of men had gonorrhoea at any site (447/3938, 11.4%, 95% CI 10.3% to 12.2%), but among these 447 men, single-site infection was less common (256/447, 57.3%, 95% CI 52.6% to 61.7%, p<0.001) and multisite infection (191/447, 42.7%, 95% CI 38.2% to 47.3%, p<0.001) was more common than chlamydia. There were also marked differences by anatomical site. Urethral infection commonly occurred as single sites (75/122, 61.5%, 95% CI 52.8% to 70.1%) for chlamydia but uncommonly occurred for gonorrhoea (12/100, 12.0%, 95% CI 5.6% to 18.3%, p<0.001). In contrast, anorectal infection uncommonly occurred as multisite infection for chlamydia (98/394, 24.9%, 95% CI 20.6% to 29.1%) but was common (184/309, 59.5%, 95% CI 54.0% to 64.9%, p<0.001) for gonorrhoea.

Conclusions The markedly different pattern of site-specific infection for chlamydia and gonorrhoea infections among the same MSM suggests significant differences in the transmissibility between anatomical sites and the duration of each infection at each site.

  • Neisseria gonorrhoeae
  • chlamydia infection
  • sexual health
  • men

Data availability statement

All data relevant to the study are included in the article.

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Data availability statement

All data relevant to the study are included in the article.

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  • Handling editor Jo Gibbs

  • Twitter @MarjanTabesh, @kitfairley, @JHocking01, @drdebwilliamson, @LeiZhan21499561, @Cat_Bradshaw_, @EricPFChow

  • Presented at 2020 Joint Australasian HIV&AIDS and Sexual Health Conferences

  • Correction notice This article has been corrected since it first published. The provenance and peer review statement has been included.

  • Contributors EPFC and CKF conceived and designed the study. MT performed the data analysis and wrote the first draft of the manuscript. EPFC and CKF assisted with data analysis. EPFC oversaw the study. All authors contributed to data interpretation, revised the manuscript critically for important intellectual content, and reviewed and approved the final article.

  • Funding EPFC and DAW are supported by an Australian National Health and Medical Research Council (NHMRC) Emerging Leadership Investigator grant (GNT1172873 and GNT1174555, respectively). CKF and CSB are supported by an Australian NHMRC Leadership Investigator grant (GNT1172900 and GNT1173361, respectively).

  • Competing interests None declared.

  • Ethics approval and consent to participate This study was approved by the Alfred Hospital Ethics Committee, Melbourne, Australia (788/19).

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