A prospective study of absolute risk and determinants of human papillomavirus incidence among young women in Costa Rica

• Published in: BMC infectious diseases 2013-07, Vol.13 (1), p.308-308, Article 308
• Main Authors: Clarke, Megan, Schiffman, Mark, Wacholder, Sholom, Rodriguez, Ana Cecilia, Hildesheim, Allan, Quint, Wim
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Alphapapillomavirus - classification; Alphapapillomavirus - isolation & purification; Analysis; Analysis of Variance; Cervical cancer; Costa Rica - epidemiology; Female; Human papillomavirus; Human papillomavirus 16; Humans; Immunization; Incidence; Monogamy; Papillomavirus infections; Papillomavirus Infections - epidemiology; Papillomavirus Infections - virology; Papillomaviruses; Prevalence; Prevention; Proportional Hazards Models; Prospective Studies; Risk Factors; Sexual Behavior; Sexually transmitted diseases; Vaccination; Vaccines; Womens health
• ISSN: 1471-2334; 1471-2334
• DOI: 10.1186/1471-2334-13-308

High risk human papillomaviruses (HR-HPV) are known to be extremely common, sexually transmitted infections, but more information is needed regarding the absolute risks of type-specific HR-HPV infections in the years following sexual debut. We conducted a survival analysis of 3,737 women aged 18-25 from the control group of the Costa Rican Vaccine trial to determine the absolute risks of HR-HPV infections at 12 months, 24 months, and end of follow-up (average of 50.7 months). To corroborate determinants of infection, we used Cox proportional hazards methods to assess associations between demographics and sexual risk behaviors and incident HR-HPV. Cumulative incidence for HR-HPV infections was 51.3% at the end of the study period. The most common incident types were HPV52 (15.4%), HPV51 (13.6%), and HPV16 (12.4%). Type-specific cumulative incidence corresponded closely with type-specific prevalences, except that HPV16 was more prevalent than predicted by incidence, suggesting greater persistence. The strongest predictors of incident HR-HPV infections as a group in a multivariate analysis were the expected correlates of sexual behavior of the woman and her partner, such as being single (HR 1.6, 95% CI 1.4-1.8) or divorced/widowed (HR: 2.1, 95% CI: 1.7-2.7), having multiple HPV infections at enrollment (HR: 1.5, 95% CI: 1.3-1.7), and current smoking (HR: 1.2, 95% CI: 1.0-1.3). In women who reported being having only one lifetime sexual partner (being in a monogamous relationship), the strongest predictors of HR-HPV included not living with sex partner (HR: 2.1, 95% CI 1.7-2.5) and age of sex partner (HR: 1.4, 95% CI: 1.0-1.8). We confirm the extremely high incidence of HR-HPV in young women, emphasizing the importance of vaccinating young girls before sexual debut.