Seroprevalence of human papillomavirus-16,-18,-31, and -45 in a population-based cohort of 10 000 women in Costa Rica

Human papillomavirus (HPV) seroprevalence and determinants of seropositivity were assessed in a 10 049-woman population-based cohort in Guanacaste, Costa Rica. Serologic responses based on VLP-based ELISA were obtained from the plasma collected at study enrollment in 1993/1994 for HPV-16 (n = 9949), HPV-18 (n = 9928), HPV-31 (n = 9932), and HPV-45 (n = 3019). Seropositivity was defined as five standard deviations above the mean optical density obtained for studied virgins (n = 573). HPV-16, -18, -31, and -45 seroprevalence was 15, 15, 16, and 11%, respectively. Of women DNA-positive for HPV-16, -18, -31, or -45, seropositivity was 45, 34, 51, and 28%, respectively. Peak HPV seroprevalence occurred a decade after DNA prevalence; lifetime number of sexual partners was the key determinant of seropositivity independent of DNA status and age. DNA- and sero-positive women showed the highest risk for concurrent CIN3/cancer, followed by DNA- positive, sero-negative women.