Prevalence of high-risk human papillomavirus types among substance abusing women screened for cervical and anal cancer.

Purpose Prevalence studies of HPV in the general US population have provided important baseline data for monitoring HPV vaccination efforts. As the field of HPV progresses, funders are calling for HPV studies to be conducted in more meaningful and high risk populations to uncover new leads in HPV infection. Our primary objective in this cross-sectional study was to estimate the seroprevalence of high-risk HPV (hr-HPV) among a high risk population - substance abusing women. Further investigation was conducted to assess concordance of hr-HPV infection between cervical and anal sites. Methods Women were recruited from Nexus Recovery Center – the largest female only substance abuse recovery center in DFW. Cervical and anal pap smears were used to collect samples for hr-HPV co-testing. HPV results were received from 318 cervical samples and 243 anal samples. Chi-square and t-tests were used to determine differences in hr-HPV status by age, race, smoking, high risk sexual activity, cytology, and concordance. Results Seropositivity for cervical hr-HPV was 29%. Anal hr-HPV was observed significantly more often (32%) compared to cervical sites. Seropositivity for hr-HPV among women with abnormal cervical cytology was 63%; for those with normal cervical cytology hr-HPV was 47%. However, only 39% of abnormal anal cytology tested seropositive for hr-HPV. hr-HPV status differed by age and cervical cytology, but not by race, smoking, sexual activity, or anal cytology. Of those testing positive for either cervical or anal hr-HPV, nearly half (46%) had infection concurrently at both sites. Conclusion Our study population demonstrated higher rates of cervical and anal hr-HPV infections compared to US women (23% and 19%, respectively). As expected, hr-HPV status differed by cervical cytology results. Contrary to our hypothesis, hr-HPV status was similar regardless of anal cytology results. This unexpected finding may suggest a different ability of anal hr-HPV clearance, or it could reflect the younger age of our study group given the older age predilection of anal dysplasia. Concordance of hr-HPV between cervical and anal sites is generating a separate study of type-specific hr-HPV at cervical, anal, and oral sites. Our findings lend importance to determining whether anal Pap smears and/or anal hr-HPV testing should be included in well woman exams and also presents baseline HPV prevalence for the first time in this high risk population.