title: Incidence of genital warts in Sweden before and after quadrivalent human papillomavirus vaccine availability.
abstract: BACKGROUND
  More than 90% of genital warts (GW) cases are caused by human papillomavirus (HPV) types 6 and 11. The introduction of HPV vaccines necessitates the estimation of the population-based incidence of GW immediately before and after vaccination uptake.
  
  
  METHODS
  Incidence proportions were calculated using the entire population aged 10–44 years living in Sweden during 2006–2010. The Prescribed Drug Register and the National Patient Register were used to define GW episodes. Time trends were estimated using Poisson regression.
  
  
  RESULTS
  In 2010, age-stratified incidence proportions of GW were highest for 20-year-old women (956 cases/100 000), while the incidence proportion among males was greatest at the slightly older age of 24 years (1137 cases/100 000). Crude rates were marginally higher among males than among females during 2006–2007 and appeared to later diverge. Between 2008 and 2010, the overall incidence appeared to increase among males, and the incidence among females declined. Females aged 17 and 18 years had a >25% decline in GW rates between 2006 and 2010, with significant decreases through the age of 25 years.
  
  
  CONCLUSIONS
  This study provides a reasonable estimation of the incidence of GW in the Swedish population by use of register data, with results comparable to those from previous smaller studies. There was a downward trend of GW incidence among younger females between 2006 and 2010.
authors: Department of Medical Epidemiology and Biostatistics, Stockholm, Sweden. amy.leval@ki.se
authors: Amy
authors: A
authors: Leval
authors: Eva
authors: E
authors: Herweijer
authors: Lisen
authors: L
authors: Arnheim-Dahlström
authors: Hasse
authors: H
authors: Walum
authors: Emma
authors: E
authors: Frans
authors: Pär
authors: P
authors: Sparén
authors: Julia F
authors: JF
authors: Simard
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002648:Child; D003218:Condylomata Acuminata / Q000453:epidemiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D053918:Papillomavirus Vaccines / Q000008:administration & dosage / Q000276:immunology*; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D055815:Young Adult
chemical_list: D053918:Papillomavirus Vaccines