Age-specific incidence and clearance of high-risk human papillomavirus infections in women in the former Soviet Union

Abstract

Recently, conflicting results on human papillomavirus (HPV) clearance have been reported and the data on the accumulation of incident HPV infections are still fragmentary. Thus, we completed an analysis of the age-specific incidence and clearance rates of high-risk (HR) HPV infections in 448 women participating in a multi-centre screening study in three New Independent States countries. At baseline, 239 of the 448 women were negative for HR HPV DNA, whereas 209 were HR HPV-positive and cleared HR HPV during the prospective follow-up. The cumulative incidence and clearance of HR HPV were modelled using life-table techniques. The monthly incidence rates of HR HPV were significantly age dependent (p = 0.0001), whereas monthly clearance rates remained constant across the nine age groups (p = 0.920). The incidence rates (3.04% and 2.65%) exceeded the clearance rates in the two youngest age groups only, 15-20- and 21-25-year-old women, and remained lower (0-0.84%) in all other age groups. The cumulative rate of incident HR HPV infections (1.0%) was significantly lower than the overall clearance rate (1.9%) (p = 0.001). In life-table analysis, incident HR HPV infections between the nine age groups were significantly different (p = 0.0001), while cumulative HR HPV clearance was identical in all groups (p = 0.822). The accumulation of incident HR HPV infections is significantly age-related, whereas virus clearance remains constant between 15 and 60 years of age. These distinct age-specific incidence and clearance rates explain the differences in age-specific prevalence of HR HPV infections in the study population.