Cervical human papillomavirus infections in commercial sex workers-risk factors and behaviours.

We have investigated the prevalence of, and risk factors for, cervical human papillomavirus (HPV) infection in commercial sex workers (CSWs) and controls attending the same sexual health clinics in Sydney. A self-administered 'risk factor' questionnaire was completed and a Pap smear and a specimen for HPV detection and typing were taken. Results from the 288 CSWs and 266 controls were assessed by univariate and multivariate analyses. No significant difference in the rates of cervical HPV infection in CSWs (31.6%) and controls (24.4%) was found but HPV related cytological abnormalities were more common on the CSWs (P <0.05). In both groups, factors independently associated with HPV infection were the use of non-barrier contraception, cytological abnormalities, age under 36 and the number of non-paying sexual partners. A risk factor for CSWs only was sex-work in Japan. A detailed 'work' history from CSWs may be useful to identify unsafe practices or work in countries where safer sex may be less acceptable.