Distribution of 37 mucosotropic HPV types in women with cytologically normal cervical smears: The age-related patterns for high-risk and low-risk types

Before guidelines can be set for the use of high-risk human papillomavirus (HR HPV) testing in cervical cancer screening and vaccine preparation, age-related prevalence of HR HPV types in cytologically normal smears has to be known. Therefore, in a cross-sectional study the prevalence of 37 different HPV genotypes and putatively unidentified HPV types was determined in 3,305 cytologically normal cervical smears from the general female population (15-69 years of age) using an HPV general primer GP5+/bioGP6+ mediated PCR assay. Subsequently, HPV-positive cervical smears were typed for 19 HR and 18 low-risk (LR) HPVs with an enzyme immunoassay using HPV type-specific oligoprobes in cocktails and individually, respectively. Overall, -HR and -LR HPV prevalences appeared to be of 4.6%, 3.3%, and 1.0%, respectively. Twenty-six different HPV types were detected in the 152 HPV-positive samples, the most prevalent types being HPV 16, 31, and 18. With regard to age, a peak prevalence of 19.6% for all HPVs was found in women 25-29 years of age, which declined to a mean of 4.3% in women over 30 years. With regard cytologically normal cervical smears (n = 3, 011) of women participating in the population-based screening program in the Netherlands (30 to 60 years), all HR HPVs showed decreased occurrence with increasing age, whereas the prevalence of LR HPV types remained constant. We suggest that screening for abnormal cytology implies screening for HR HPV infections and the subsequent treatment results in a decline of HR HPV prevalence in contrast to LR HPV prevalence during the years of screening.