Risk factors for the acquisition of genital warts: are condoms protective?

OBJECTIVES To characterise risk factors for the acquisition of genital warts and specifically to determine whether condoms confer protection from infection. METHODS A retrospective case-control study comparing demographic, behavioural, and sexual factors in men and women with and without newly diagnosed genital warts, who attended Sydney Sexual Health Centre (SSHC), an inner city public sexual health centre, in 1996. Data were extracted from the SSHC database. Crude odds ratios (OR) were calculated to compare cases and controls and significant factors were then controlled for using multivariate logistic regression to obtain adjusted odds ratios (ORs). RESULTS 977 patients with warts and 977 controls matched by sex and date of attendance were included. In both sexes, univariate analysis revealed that younger age, more lifetime sexual partners, failure to use condoms, greater cigarette smoking and alcohol consumption were associated with warts, and there was a negative association with previous infection with Chlamydia trachomatis, Neisseria gonorrhoeae, hepatitis B, and genital herpes. In males, on multivariate analysis, factors which remained significant were younger age, more lifetime sexual partners; failure to use condoms, greater cigarette smoking, and previous chlamydia. In women, factors which remained significant were younger age, more lifetime sexual partners, condom use, marital status, and previous infections with Chlamydia trachomatis and herpes. CONCLUSIONS Independent risk factors for genital warts include younger age, greater number of lifetime sexual partners, and smoking. Consistent condom use significantly reduces the risk of acquiring genital warts.