Prevalence of high-risk human papillomavirus and cervical intraepithelial neoplasias in a previously unscreened population--a pooled analysis from three studies.

Population prevalence of human papillomavirus (HPV) and cervical intraepithelial neoplasias (CIN) is an important indicator to judge the disease burden in the community, to monitor the performance of cervical cancer screening program and to assess the impact of HPV vaccination program. India being a country without any cervical cancer screening program has no published data on the population prevalence of CIN and only a few large community-based studies to report the high-risk HPV prevalence. The objective of our study was to study HPV and CIN prevalence in a previously unscreened population. We pooled together the results of three research studies originally designed to assess the performance of visual inspection after acetic acid application and Hybrid Capture 2 (HC 2). Nearly 60% of the screened women had colposcopy irrespective of their screening test results. The diagnosis and grading of cervical neoplasias were based on histology. The age standardized prevalence of HPV by HC 2 test was 6.0%. Age-adjusted prevalence of CIN1 and CIN2 was 2.3% and 0.5%, respectively. The age-adjusted prevalence of CIN3 was 0.4% and that of invasive cancer was 0.2%. The prevalence of high-risk HPV was relatively low in the population we studied, which is reflected in the low prevalence of high-grade CIN. The prevalence of CIN3 remained constant across age groups due to absence of screening.