Risk factors for syphilis infection in men who have sex with men: results of a case–control study in Lille, France
- Karen Champenois1,2,
- Anthony Cousien2,
- Bakhao Ndiaye3,
- Yougoudou Soukouna3,
- Véronique Baclet4,
- Isabelle Alcaraz4,
- Philippe Choisy4,
- Pascal Chaud3,
- Annie Velter5,
- Anne Gallay5,
- Yazdan Yazdanpanah1,4,6,7
- 1ATIP-Avenir Inserm: “Modélisation, Aide à la Décision, et Coût-Efficacité en Maladies Infectieuses”, Lille, France
- 2EA2694, Faculté Lille-Nord de France, Lille, France
- 3Institut de Veille Sanitaire, Lille, France
- 4Service Universitaire des Maladies Infectieuses et du Voyageur, Centre Hospitalier de Tourcoing, Tourcoing, France
- 5Institut de Veille Sanitaire, Saint-Maurice, France
- 6Service des Maladies Infectieuses et Tropicales, Hôpital Bichat Claude Bernard, Paris, France
- 7Université Denis Diderot, Paris, France
- Correspondence to Karen Champenois, ATIP-Avenir, Inserm U995, Parc Eurasanté, 152 rue du Professeur Yersin, 59120 Lille, France;
Contributors All authors contributed to the study. PC and YY had the idea of the study. KC, IA, PC, AG and YY contributed substantially to conception, design and feasibility of the study. KC wrote the protocol of the study. VA and KC wrote the questionnaires. KC coordinated the study. VB and IA contributed to acquisition of data, and YS and PC were responsible for the management of the data. KC and AC performed the statistical analysis and presented results. All authors participated to interpretation of results. KC and YY drafted the article. All authors revised the manuscript critically for important intellectual content and approved the final version to be published.
- Accepted 6 May 2012
- Published Online First 7 June 2012
Background Substantial increases in syphilis have been reported since the early 2000s in northern countries, particularly among men who have sex with men (MSM). The authors aimed to identify risk factors for early syphilis in MSM in Lille, a large urban area of northern France.
Methods A matched case–control study was conducted in MSM aged ≥18 years. Cases were diagnosed with primary, secondary or early latent syphilis between April 2008 and June 2010. Controls sought care in STIs clinics or were followed in an HIV clinic. Controls had no history of and no current syphilis. They were matched to cases for age and HIV status. Multivariate conditional logistic regression models were used to identify risk factors for early syphilis.
Results 53 patients with early syphilis were enrolled. Average age was 37 years, and 47% were HIV-infected. For analysis, they were matched to 90 controls. Factors associated with syphilis were: low educational attainment (OR=5.38, 95% CI 1.94 to 14.94; p=0.001), receptive oral sex with casual male partners without a condom (OR=4.86, 95% CI 1.63 to 14.48; p=0.005) and anal sex toy use with casual male partners (OR=2.72, 95% CI 1.01 to 7.32; p=0.05). Seeking of sex partners online (OR=5.17, 95% CI 1.33 to 20.11), use of poppers (OR=2.2, 95% CI 1.1 to 4.3) and erectile dysfunction drugs (OR=1.9, 95% CI 1.0 to 13.2) were associated with syphilis only in the univariate analysis.
Conclusions Receptive oral sex without a condom and use of anal sex toys were identified as presenting a major risk of syphilis infection. Although these practices have been shown to present low risk of HIV transmission, the general public is unaware of their impact on transmission of other STIs.
- case–control study
- gay men
- infectious diseases
- public health
- clinical trials
- sexual behaviour
- sexual practices
Funding This work was supported by the Groupe Régional de Santé Publique (GRSP) Nord-Pas de Calais, France. Funders had no role in the conduction of the study or in the preparation of the manuscript.
Competing interests YY had received travel grants, honoraria for presentation at workshops and consultancy honoraria from Bristol-Myers Squibb, Gilead, Glaxo-SmithKline, Merck, Pfizer, Roche and Tibotec. Other authors report no conflict of interest.
Ethics approval Ethics approval was provided by CCTIRS and CNIL (French authorities).
Provenance and peer review Not commissioned; externally peer reviewed.