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

OBJECTIVE: Cross-sectional analyses of our 10,000-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. STUDY DESIGN: 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. RESULTS: 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. CONCLUSIONS: 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.