Condom use is high among female sex workers (FSW) in Amsterdam, but because of limited condom induced protection against human papillomavirus (HPV) infection, FSW may be still at high risk of HPV infection and HPV-related diseases. We aimed to study risk factors, prevalence and concordance of genital and anal high-risk(hr) HPV infection among FSW in Amsterdam.
In 2016, FSW aged ≥18 years having a consultation regarding sexually transmitted infections (STI) with the Prostitution and Health Center (PG292) in Amsterdam were invited to participate. Participation entailed taking a vaginal and anal self-swab. Demographics and sexual behavior data were collected in the consultation and HPV DNA was analyzed using SPF10-PCR-DEIA-LiPA25-system, version 1. Uni- and multivariable logistic regression analyses were performed to assess determinants of type-specific vaginal and anal hrHPV infection. Determinants of vaginal and anal hrHPV infection were uni- and multivariably assessed using logistic regression with generalized estimating equations (GEE).
We included 304 FSW with a median age of 29 years (IQR 25-37). The STI prevalence at moment of inclusion was 9% and the prevalence of vaginal and anal hrHPV among participants was 46% and 55%, respectively. The most prevalent vaginal hrHPV infections were types 31 (11.8%), 52 (10.2%), 51 (8.6%) , and 16 (8.2%). The most prevalent anal hrHPV infections were types 51 (14.1%), 31 (12.8%), 16 (11.5%) and 18 (12.2%). The highest concordance between vaginal and anal infections was found in types 31 (5.6%), 52 (4.6%), 18 (4.3%) and 16 (3.9%). A risk factor for both vaginal and anal hrHPV was opposite anatomical site of infection (OR 1.32, 95%CI 1.24-1.40; OR 1.40, 95%CI 1.31-1.50, respectively). Additionally, a risk factor for vaginal hrHPV was region of birth (Eastern Europe OR 0.95, 95%CI 0.93-0.97; America’s OR 0.96, 95% CI 0.94-0.99; other regions OR 0.95, 95% CI 0.93-0.98; compared to the Netherlands).
Vaginal and anal hrHPV prevalence is high among FSW in Amsterdam, the Netherlands. Even in multivariable logistic regression using GEE, concordance between vaginal and anal type-specific hrHPV infections was high.