Chlamydia trachomatis transmission between the oropharynx, urethra and anorectum in men who have sex with men: a mathematical model

Xianglong Xu, Eric P. F. Chow, Jason J. Ong, Christian J. P. A. Hoebe, Zhuoru Zou, Jane S. Hocking, Christopher K. Fairley, Lei Zhang*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

9 Citations (Web of Science)

Abstract

Background It has been presumed that Chlamydia trachomatis is transmitted between men only through anal or oral sex, but no mathematical models have tested this presumption. Methods To test this presumption, we created 20 compartmental mathematical models of different sexual practices that included both oral and anal sex and calibrated these models to the observed rates of Chlamydia trachomatis infection at three anatomical sites from 4888 men who have sex with men (MSM) in Melbourne Sexual Health Centre during 2018-2019. Results A model that included only oral and anal sex could replicate the observed rates of single-site infection at the oropharynx, urethra and rectum alone, but could not replicate infection at more than one of these sites (multisite). However, if we included transmission from sexual practices that followed one another in the same sexual episode (e.g. saliva contamination of the penis from oral sex transmitting chlamydia to the rectum by anal sex), we significantly improved the calibration of multisite infection rates substantially. Conclusions Our modelling study suggests that transmission routes other than just oral and anal sex are necessary to explain the high rate of Chlamydia trachomatis infection at more than one site.

Original languageEnglish
Article number326
Number of pages10
JournalBMC Medicine
Volume18
Issue number1
DOIs
Publication statusPublished - 17 Nov 2020

Keywords

  • Transmission
  • Behavioural interventions
  • Sexual practices
  • Anatomical site
  • Chlamydia trachomatis
  • Men who have sex with men
  • SEXUALLY-TRANSMITTED INFECTIONS
  • NEISSERIA-GONORRHOEAE
  • PREEXPOSURE PROPHYLAXIS
  • HOMOSEXUAL-MEN
  • RISK-FACTORS
  • SALIVA USE
  • ANAL SEX
  • HEALTH
  • IMPACT
  • HIV

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