title: Natural history of genital warts: analysis of the placebo arm of 2 randomized phase III trials of a quadrivalent human papillomavirus (types 6, 11, 16, and 18) vaccine.
abstract: BACKGROUND
  The placebo arm of human papillomavirus (HPV) vaccine trials helps define the natural history of genital warts (GW).
  
  
  METHODS
  Women enrolled in the placebo arm (n = 8800) of 2 randomized trials of a quadrivalent vaccine were examined for the presence of GW for up to 9 visits over approximately 4 years. A comprehensive examination of the perianal area, vulva, and vagina prompted biopsy. Biopsy samples were analyzed by a blinded panel of up to 4 histopathologists and tested for 14 HPV genotypes (6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 59) by use of a polymerase chain reaction-based assay. Risk factors for the development of GW were assessed.
  
  
  RESULTS
  Women were followed up for an average of 3.6 years (range, 0-4.9 years). Overall, 298 (3.4%) of 8800 participants developed GW related to HPV-6 or HPV-11 (incidence rate, 0.87 cases per 100 person-years-at-risk). In total, 520 distinct lesions were diagnosed as GW. HPV DNA was detected in 472 (90.8%) lesions, with HPV-6 and HPV-11 detected in 447 (86.0%) of these lesions (94.7% of 472 HPV DNA-positive lesions). We found high-risk HPV types in 161 (31.0%) of 520 lesions. Risk factors for HPV-6- and HPV-11-related GW included infection at baseline, acquisition of new sex partners, a higher number of sex partners, and DNA positivity at baseline for a high-risk HPV type.
  
  
  CONCLUSIONS
  We confirm the major role played by HPV-6 and HPV-11 in GW, as well as associated risk factors. A vaccine that includes these types of HPV could substantially reduce the overall burden of HPV disease.
authors.affiliation: Microbiology and Infectious Diseases Department, Royal Women's Hospital, 132 Grattan Street, Carlton, Victoria 3053, Australia. suzanne.garland@thewomens.org.au
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Garland
authors.forename: Marc
authors.initials: M
authors.lastname: Steben
authors.forename: Heather L
authors.initials: HL
authors.lastname: Sings
authors.forename: Margaret
authors.initials: M
authors.lastname: James
authors.forename: Shuang
authors.initials: S
authors.lastname: Lu
authors.forename: Radha
authors.initials: R
authors.lastname: Railkar
authors.forename: Eliav
authors.initials: E
authors.lastname: Barr
authors.forename: Richard M
authors.initials: RM
authors.lastname: Haupt
authors.forename: Elmar A
authors.initials: EA
authors.lastname: Joura
mesh_terms: D000293:Adolescent; D000328:Adult; D017326:Clinical Trials, Phase III as Topic; D003218:Condylomata Acuminata / Q000453:epidemiology / Q000276:immunology*; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D052162:Human papillomavirus 16 / Q000235:genetics / Q000276:immunology*; D052161:Human papillomavirus 18 / Q000235:genetics / Q000276:immunology*; D052163:Human papillomavirus 6 / Q000235:genetics / Q000276:immunology*; D006801:Humans; D030361:Papillomavirus Infections / Q000453:epidemiology / Q000276:immunology* / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D013997:Time Factors; D014765:Viral Vaccines / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D014765:Viral Vaccines