title: Incidence and duration of type-specific human papillomavirus infection in high-risk HPV-naïve women: results from the control arm of a phase II HPV-16/18 vaccine trial.
abstract: Persistence of human papillomaviruses (HPVs) is necessary for cervical carcinogenesis. We evaluated incidence and duration of type-specific HPV infections and the influence of age and number of sexual partners.
  
  
  
  Data were obtained from 553 women (15-25 years), who were seronegative and DNA-negative for high-risk HPV (HR-HPV) types and were enrolled in the placebo arm of a randomised trial of the HPV-16/18 vaccine (NCT00689741/NCT00120848). They were followed for 6.3 years. Cervicovaginal samples were self-collected at 3-month intervals for up to 27 months, and cervical samples were collected by clinicians at 6-month intervals until study end. Samples were tested for HPV types using a broad-spectrum PCR assay. Incidence rate ratios (RRs) and 95% CIs were used to estimate the association among age, sexual habits and HPV acquisition.
  
  
  
  Incidence rates (95% CI) using cervical samples were 11.8 (10.4 to 13.4) and 5.6 (4.7 to 6.6) per 1000 women-months for HR-HPVs and low-risk HPVs (LR-HPVs), respectively. Equivalent rates in combined cervicovaginal and cervical samples were 17.2 (15.4 to 19.2) and 6.9 (5.9 to 8.0), respectively. 54 per cent of HR-HPV types from combined cervicovaginal and cervical samples persisted for 1 year compared with 32.3% for LR-HPV types. The risk of acquiring any HPV infection was higher among women aged <21 years (RR=1.33, 95% CI 1.1 to 1.7) and women having >1 sexual partner (RR=1.83, 95% CI 1.4 to 2.4) at baseline.
  
  
  
  HR-HPV infections were more common and lasted longer on average than LR-HPV infections. HPV acquisition was more common in younger women with multiple sexual partners.
  
  
  
  NCT00689741, NCT00120848; Post-results.
authors: Division of Cancer Epidemiology, McGill University, Montreal, Quebec, Canada.
authors: Agnihotram V
authors: AV
authors: Ramanakumar
authors: Federal University of Rio Grande do Sul-UFRGS/HCPA-Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
authors: Paulo
authors: P
authors: Naud
authors: Leonor M de Barros Hospital, São Paulo, Brazil.
authors: Cecilia M
authors: CM
authors: Roteli-Martins
authors: Department of Gynecology and Obstetrics, Gynecology and Obstetrics Infectious Diseases Sector, University of Parana, Curitiba, Parana, Brazil.
authors: Newton S
authors: NS
authors: de Carvalho
authors: Instituto de Prevenção do Câncer, Fortaleza, Brazil.
authors: Paola C
authors: PC
authors: de Borba
authors: Department of Gynecology, Oncology Division, State University of Campinas, Campinas, Brazil.
authors: Julio C
authors: JC
authors: Teixeira
authors: Pediatric Alliance, Pittsburgh, Pennsylvania, USA.
authors: Mark
authors: M
authors: Blatter
authors: Department of Pediatrics, University of California, San Francisco, California, USA.
authors: Anna-Barbara
authors: AB
authors: Moscicki
authors: Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA.
authors: Diane M
authors: DM
authors: Harper
authors: University of Alberta, Edmonton, Alberta, Canada.
authors: Barbara
authors: B
authors: Romanowski
authors: Departments of Microbiology/Molecular Genetics, Dermatology & Internal Medicine, The University of Texas Medical School, Houston, Texas, USA.
authors: Stephen K
authors: SK
authors: Tyring
authors: First Line Medical Services Ltd., St. John's, Newfoundland and Labrador, Canada.
authors: Brian
authors: B
authors: Ramjattan
authors: GSK Vaccines, King of Prussia, Pennsylvania, USA.
authors: Anne
authors: A
authors: Schuind
authors: GSK Vaccines, King of Prussia, Pennsylvania, USA.
authors: Gary
authors: G
authors: Dubin
authors: Division of Cancer Epidemiology, McGill University, Montreal, Quebec, Canada.
authors: Eduardo L
authors: EL
authors: Franco
mesh_terms: D000293:Adolescent; D000328:Adult; D004279:DNA, Viral / Q000032:analysis; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D015994:Incidence; D027383:Papillomaviridae / Q000235:genetics* / Q000302:isolation & purification; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000517:prevention & control*; D053918:Papillomavirus Vaccines / Q000008:administration & dosage*; D012307:Risk Factors; D012747:Sexual Partners; D013997:Time Factors; D002583:Uterine Cervical Neoplasms / Q000517:prevention & control; D055815:Young Adult
chemical_list: D004279:DNA, Viral; D053918:Papillomavirus Vaccines
keywords: Cervical cancer; Cohort study; EPIDEMIOLOGY; Human papillomavirus; Natural history