title: Natural history of anal human papillomavirus infection in heterosexual women and risks associated with persistence.
abstract: BACKGROUND
  Anal cancer is more common in women than in men, yet little is known about the natural history of human papillomavirus (HPV) in women. The objective was to examine the natural history of anal HPV in heterosexual women.
  
  
  METHODS
  Young women participating in an HPV cohort study were seen at 4-month intervals for cervical and anal HPV testing. Time to clearance was estimated using the Kaplan-Meier approach; risks for persistence were assessed using Cox regression models.
  
  
  RESULTS
  Seventy-five women (mean age, 23.5 ± 4.1 years) who tested positive for anal HPV were followed for a mean of 84.5 ± 44.9 months. By 3 years, 82.5% of anal non-16 high-risk (HR) HPV, 82.6% of low-risk (LR) HPV, and 76.2% of HPV-16 infections had cleared. By 3 years, only 36.4% of women had become negative for all HPV types. In the multivariable model, concurrent cervical HPV-16 (P < .001), weekly alcohol use (P = .015), anal touching during sex (P = .045), recent anal sex (P = .04), and no condom use during anal sex (P = .04) were associated with HPV-16 persistence. Greater number of new sex partners (P = .024) and condom use during vaginal sex (P = .003) were associated with clearance. Similar associations were found for clearance in all HR-HPV infections. Only concomitant cervical HPV was associated with non-16 HR-HPV persistence.
  
  
  CONCLUSIONS
  The majority of anal HPV infections cleared within 3 years. HPV-16 infections were slower to clear than other HR-HPV infections, consistent with its role in anal cancer. Specific sexual behaviors were associated with persistence, suggesting that education and behavioral interventions may decrease persistence.
authors.affiliation: Division of Adolescent Medicine, Department of Pediatrics.
authors.forename: Anna-Barbara
authors.initials: AB
authors.lastname: Moscicki
authors.forename: Yifei
authors.initials: Y
authors.lastname: Ma
authors.forename: Sepideh
authors.initials: S
authors.lastname: Farhat
authors.forename: Julie
authors.initials: J
authors.lastname: Jay
authors.forename: Evelyn
authors.initials: E
authors.lastname: Hanson
authors.forename: Susanna
authors.initials: S
authors.lastname: Benningfield
authors.forename: Janet
authors.initials: J
authors.lastname: Jonte
authors.forename: Cheryl
authors.initials: C
authors.lastname: Godwin-Medina
authors.forename: Robert
authors.initials: R
authors.lastname: Wilson
authors.forename: Stephen
authors.initials: S
authors.lastname: Shiboski
mesh_terms: D000328:Adult; D001004:Anus Diseases / Q000821:virology*; D015331:Cohort Studies; D005260:Female; D020010:Heterosexuality; D006801:Humans; D053208:Kaplan-Meier Estimate; D027383:Papillomaviridae / Q000145:classification / Q000302:isolation & purification*; D030361:Papillomavirus Infections / Q000821:virology*; D016016:Proportional Hazards Models; D012725:Sexual Behavior; D002577:Uterine Cervical Diseases / Q000821:virology; D055815:Young Adult
keywords: anal; human papillomavirus infection; persistence; women