title: Prevalence of human papillomavirus (HPV) infections in sexually active adolescents and young women in England, prior to widespread HPV immunisation.
abstract: BACKGROUND
  The introduction of an HPV immunisation programme in England should result in a significant reduction in the prevalence of vaccine type infections in young women. Here we describe type-specific HPV prevalence in three samples of the young female population in England, prior to the beginning of mass immunisation in 2008.
  
  
  METHODS
  Residual vulva-vaginal swab samples from females aged under 25 years undergoing chlamydia testing as part of the National Chlamydia Screening Programme (NCSP) or Prevention of Pelvic Infection (POPI) trial were collected from sites across England, together with available demographic and sexual behaviour data. Residual samples were screened for HPV infection using the Hybrid Capture 2 (hc2) HPV DNA Test, including the high-risk (HR) and low-risk (LR) probes. Hc2 positive samples were genotyped using the Roche Linear Array (LA) HPV Genotyping Test.
  
  
  RESULTS
  A total of 3829 samples were included: 2369 from 16 to 24 year old NCSP participants, 275 from 13 to 15 year old NCSP participants and 1185 from 16 to 24 year old POPI participants. Variations in HPV prevalence between and within the different samples followed a pattern largely consistent with differences in sexual behaviour. The prevalence of total HR HPV infection, of HPV 16 and/or 18 (16/18) infection and of five HR HPV types closely related to HPV 16/18 (HPV 31, 33, 45, 52 or 58) amongst 16-24 year old NCSP participants was 35% (95% CI 33-37%), 18% (95% CI 16-19%), and 16% (95% CI 14-18%), respectively. Risk of HR HPV infection increased with age during the teen years and was higher in women who reported two or more sexual partners in the last year and in women with chlamydia infection. Approximately half of women with HPV 16/18 infection also had another non-vaccine HR HPV type present.
  
  
  CONCLUSIONS
  Prior to HPV immunisation, there was a high prevalence of HPV infections in the lower genital tract of young, sexually active females in England. The overall, type-specific, and multiple infection prevalence closely reflected age and sexual activity. These data provide a baseline against which the early impact of HPV immunisation on the prevalence of HPV 16/18 and closely related types in young women can be measured, in order to inform immunisation and cervical screening policies.
authors.affiliation: HIV/STI Department, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, United Kingdom.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Howell-Jones
authors.forename: Natasha
authors.initials: N
authors.lastname: de Silva
authors.forename: Mercy
authors.initials: M
authors.lastname: Akpan
authors.forename: Pippa
authors.initials: P
authors.lastname: Oakeshott
authors.forename: Caroline
authors.initials: C
authors.lastname: Carder
authors.forename: Lindsay
authors.initials: L
authors.lastname: Coupland
authors.forename: Margaret
authors.initials: M
authors.lastname: Sillis
authors.forename: Harry
authors.initials: H
authors.lastname: Mallinson
authors.forename: Vic
authors.initials: V
authors.lastname: Ellis
authors.forename: David
authors.initials: D
authors.lastname: Frodsham
authors.forename: T Ian
authors.initials: TI
authors.lastname: Robinson
authors.forename: O Noel
authors.initials: ON
authors.lastname: Gill
authors.forename: Simon
authors.initials: S
authors.lastname: Beddows
authors.forename: Kate
authors.initials: K
authors.lastname: Soldan
mesh_terms: D000293:Adolescent; D003430:Cross-Sectional Studies; D004739:England / Q000453:epidemiology; D005260:Female; D005838:Genotype; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods; D027383:Papillomaviridae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D030361:Papillomavirus Infections / Q000453:epidemiology*; D015995:Prevalence; D012725:Sexual Behavior / Q000706:statistics & numerical data; D014621:Vagina / Q000821:virology; D014773:Virology / Q000379:methods; D014844:Vulva / Q000821:virology; D055815:Young Adult