title: A cohort effect of the sexual revolution may be masking an increase in human papillomavirus detection at menopause in the United States.
abstract: BACKGROUND
  Cohort effects, new sex partnerships, and human papillomavirus (HPV) reactivation have been posited as explanations for the bimodal age-specific HPV prevalence observed in some populations; no studies have systematically evaluated the reasons for the lack of a second peak in the United States.
  
  
  METHODS
  A cohort of 843 women aged 35-60 years were enrolled into a 2-year, semiannual follow-up study. Age-specific HPV prevalence was estimated in strata defined by a lower risk of prior infection (<5 self-reported lifetime sex partners) and a higher risk of prior infection (≥ 5 lifetime sex partners). The interaction between age and lifetime sex partners was tested using likelihood ratio statistics. Population attributable risk (PAR) was estimated using Levin's formula.
  
  
  RESULTS
  The age-specific prevalence of 14 high-risk HPV genotypes (HR-HPV) declined with age among women with <5 lifetime sex partners but not among women with ≥ 5 lifetime sex partners (P = .01 for interaction). The PAR for HR-HPV due to ≥ 5 lifetime sex partners was higher among older women (87.2%), compared with younger women (28.0%). In contrast, the PAR associated with a new sex partner was 28% among women aged 35-49 years and 7.7% among women aged 50-60 years.
  
  
  CONCLUSIONS
  A lower cumulative probability of HPV infection among women with a sexual debut before the sexual revolution may be masking an age-related increase in HPV reactivation in the United States.
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD21205, USA. pgravitt@jhsph.edu
authors.forename: Patti E
authors.initials: PE
authors.lastname: Gravitt
authors.forename: Anne F
authors.initials: AF
authors.lastname: Rositch
authors.forename: Michelle I
authors.initials: MI
authors.lastname: Silver
authors.forename: Morgan A
authors.initials: MA
authors.lastname: Marks
authors.forename: Kathryn
authors.initials: K
authors.lastname: Chang
authors.forename: Anne E
authors.initials: AE
authors.lastname: Burke
authors.forename: Raphael P
authors.initials: RP
authors.lastname: Viscidi
mesh_terms: D000328:Adult; D000367:Age Factors; D015988:Cohort Effect; D005260:Female; D006801:Humans; D008593:Menopause; D008875:Middle Aged; D027383:Papillomaviridae; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000821:virology; D047648:Perimenopause; D012725:Sexual Behavior; D012747:Sexual Partners; D014412:Tumor Virus Infections / Q000453:epidemiology* / Q000821:virology; D014481:United States / Q000453:epidemiology; D014775:Virus Activation