The natural history of human papillomavirus infection and cervical intraepithelial neoplasia among young women in the Guanacaste cohort shortly after initiation of sexual life

Cross-sectional analyses of our 10000-woman population-based Guanacaste cohort suggest a lag of >10 years between the peak of human papillomavirus (HPV) infection and the later peak of cervical intraepithelial neoplasia grade 3 (CIN 3). We wanted to explore early HPV natural history and CIN 3 prospectively. As part of the Guanacaste cohort we followed 206 initially virginal women aged 18 to 26 semiannually for a median of 3.6 years after initiation of sexual life. A total of 53.4% of women tested positive during the study for >/= 1 HPV type. Very few infections persisted for >1 to 2 years. Three women had histologically confirmed CIN 3 of which 2 showed persistent HPV 16. The other had serologic evidence of HPV 31. HPV infection occurs frequently and clears rapidly in most young women initiating sexual intercourse. Persistent HPV 16 can cause early CIN 3. The peak age for CIN 3 will decline with the increased screening intensity and sensitivity typical of longitudinal studies. (authors)