title: A prospective study of age trends in cervical human papillomavirus acquisition and persistence in Guanacaste, Costa Rica.
abstract: BACKGROUND
  Cross-sectional human papillomavirus (HPV) DNA prevalence peaks at young ages, reflecting sexual acquisition and typically rapid clearance. In some populations, HPV prevalence demonstrates a second peak in older women. Longitudinal data may help to explain this second peak.
  
  
  METHODS
  We followed a population-based cohort of 7237 women in Guanacaste, Costa Rica, in which we had previously observed a second peak in the baseline HPV prevalence in older women. We tested for >40 HPV types by polymerase chain reaction. We analyzed age-specific patterns of acquisition and persistence 5-7 years after enrollment for individual HPV types.
  
  
  RESULTS
  At enrollment and follow-up, cross-sectional data revealed U-shaped age-specific HPV prevalence curves for virtually every type, with higher prevalences in the younger and older women than in the middle-aged women. Prospectively, acquisition of types decreased significantly as women aged (PTrend<.05, for both), with the highest peak in young women and a secondary minor peak in older women. Type-specific persistence of HPV increased with age (PTrend<.0001). Overall, HPV acquisition predominated at younger ages, whereas persistent infections gradually became more prominent with age (PTrend<.0001).
  
  
  CONCLUSIONS
  Newly apparent infections decreased, whereas persistence increased, with age; this latter tendency supports the utility of HPV screening in older women.
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892-7234, USA. castlep@mail.nih.gov
authors.forename: Philip E
authors.initials: PE
authors.lastname: Castle
authors.forename: Mark
authors.initials: M
authors.lastname: Schiffman
authors.forename: Rolando
authors.initials: R
authors.lastname: Herrero
authors.forename: Allan
authors.initials: A
authors.lastname: Hildesheim
authors.forename: Ana Cecilia
authors.initials: AC
authors.lastname: Rodriguez
authors.forename: M Concepcion
authors.initials: MC
authors.lastname: Bratti
authors.forename: Mark E
authors.initials: ME
authors.lastname: Sherman
authors.forename: Sholom
authors.initials: S
authors.lastname: Wacholder
authors.forename: Robert
authors.initials: R
authors.lastname: Tarone
authors.forename: Robert D
authors.initials: RD
authors.lastname: Burk
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002584:Cervix Uteri / Q000821:virology*; D003364:Costa Rica / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D027383:Papillomaviridae; D030361:Papillomavirus Infections / Q000453:epidemiology*; D015995:Prevalence; D011446:Prospective Studies