title: Risk factors for HPV DNA detection in middle-aged women.
abstract: OBJECTIVE
  Strong epidemiologic evidence indicates that human papillomavirus (HPV) is the main etiologic factor of cervical cancer. A few cohort studies suggest that most HPV infections are transient in young women and that persistent HPV infections are more common in older women. Little is known about the determinants of persistent HPV infections. The present study was aimed at increasing our knowledge about these determinants.
  
  
  OBJECTIVE
  To identify risk factors for genital HPV DNA detection among cytologically normal middle-aged women.
  
  
  METHODS
  Eight hundred ten women who participated as control subjects in three case-control studies on cervical cancer in Spain, Colombia, and Brazil were included in this study. After an interview, women underwent a gynecologic examination with collection of exfoliated cells for a Papanicolaou smear and HPV DNA detection. Human papilloma virus DNA was detected by polymerase chain reaction (PCR)-based hybridization techniques.
  
  
  RESULTS
  The HPV positivity rate was 10.5% in the whole population, but was higher in the areas with high incidence of cervical cancer (17% in Brazil and 13% in Colombia) than in Spain (4.9%), which is a low-risk area for cervical cancer. Age was related to the prevalence of HPV DNA in Brazil, but not in Spain and Colombia. In univariate analyses in all three countries, the prevalence of HPV DNA was positively associated with the number of lifetime sexual partners and inversely associated with the levels of family income and with age at first sexual intercourse. There was four times increase in the odds ratio (OR) of HPV infection in women who had six or more lifetime sexual partners compared with those with one or less. The use of any kind of contraceptive tended to decrease the OR for HPV detection. Their ORs ranged from 0.44 (barrier methods) to 0.48 (oral contraceptives). In Spain and Colombia, antibodies against Chlamydia trachomatis were positively associated with the prevalence of HPV DNA. In a final multivariate model, the positive associations with lifetime number of sexual partners, socioeconomic status, and C. trachomatis persisted.
  
  
  CONCLUSIONS
  These results support the sexual transmission of HPV and suggest that socioeconomic status and antibodies to C. trachomatis are independent predictors of HPV detection in middle-aged cytologically normal women.
authors.affiliation: Unit of Field and Intervention Studies, International Agency for Research on Cancer, Lyon, France.
authors.forename: N
authors.initials: N
authors.lastname: Muñoz
authors.forename: I
authors.initials: I
authors.lastname: Kato
authors.forename: F X
authors.initials: FX
authors.lastname: Bosch
authors.forename: J
authors.initials: J
authors.lastname: Eluf-Neto
authors.forename: S
authors.initials: S
authors.lastname: De Sanjosé
authors.forename: N
authors.initials: N
authors.lastname: Ascunce
authors.forename: M
authors.initials: M
authors.lastname: Gili
authors.forename: I
authors.initials: I
authors.lastname: Izarzugaza
authors.forename: P
authors.initials: P
authors.lastname: Viladiu
authors.forename: M J
authors.initials: MJ
authors.lastname: Tormo
authors.forename: P
authors.initials: P
authors.lastname: Moreo
authors.forename: L C
authors.initials: LC
authors.lastname: Gonzalez
authors.forename: L
authors.initials: L
authors.lastname: Tafur
authors.forename: J M
authors.initials: JM
authors.lastname: Walboomers
authors.forename: K V
authors.initials: KV
authors.lastname: Shah
mesh_terms: D000328:Adult; D000367:Age Factors; D001938:Brazil / Q000453:epidemiology; D002690:Chlamydia Infections / Q000150:complications; D002692:Chlamydia trachomatis; D003105:Colombia / Q000453:epidemiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D027383:Papillomaviridae; D030361:Papillomavirus Infections / Q000453:epidemiology*; D016133:Polymerase Chain Reaction; D015995:Prevalence; D017584:Reproductive History; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012725:Sexual Behavior; D012959:Socioeconomic Factors; D013030:Spain / Q000453:epidemiology; D014412:Tumor Virus Infections / Q000453:epidemiology*