Objective: Cross-sectional analyses of our 10,000-woman, population-based Guanacaste cohort suggest a lag of > or =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 > or =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.