title: Age and geographic variability of human papillomavirus high-risk genotype distribution in a large unvaccinated population and of vaccination impact on HPV prevalence.
abstract: BACKGROUND
  The prevalence of infections with human papillomavirus (HPV) specific genotypes differs by age and areas. Knowledge of these differences will help predicting how prophylactic HPV vaccination and screening program could best be integrated.
  
  
  OBJECTIVE
  To investigate variations in the HPV distribution between areas and ages in Italy and the impact of vaccination on HPV prevalence.
  
  
  METHODS
  37,367 women aged 25-60 years who attended cervical screening in eight different areas in Northern and Central Italy were tested for HPV infection with the high-risk hybrid capture (hr-HC2) assay. hr-HC2 positive samples were genotyped by an intensive integrated strategy.
  
  
  RESULTS
  hr-HPV types were detected in 79.1% of HC2 positive women. HPV16 was the most frequent type, followed by HPV31, HPV18 and HPV56. A statistically significant variability in HPV type distribution between centres (overall χ84df(2)=195.86p<0.001) was observed. No significant overall difference in the HPV type distribution was observed in the age groups 25-34, 35-44 and 45-60 years. Considering cross-protection, overall 57.6% (95%CI 56.0-59.3) of all infections by hr-HPV types was preventable by vaccination with the bivalent vaccine and 49% (95%CI 46.9-51.1) with the quadrivalent vaccine. The variability between centres was statistically significant with both bivalent (χ7df(2)=43.8, p<0.0001) and quadrivalent vaccine (χ7df(2)=32.9, p<0.0001).
  
  
  CONCLUSIONS
  We observed differences in HPV genotype distribution according to centres but not to age. Results suggest that the higher proportion of HPV16/18 related high grade CIN in younger women could be the result of faster progression and not of earlier infection by these types.
authors.affiliation: ISPO Cancer Prevention and Research Institute, Via Cosimo il Vecchio 2, 50139 Florence, Italy. Electronic address: f.carozzi@ispo.toscana.it.
authors.forename: Francesca
authors.initials: F
authors.lastname: Carozzi
authors.affiliation: Cancer Epidemiology Unit - C.E.R.M.S., University of Turin, Via Santena 7, 10126 Turin, Italy. Electronic address: ldemarco@cittadellasalute.to.it.
authors.forename: Laura
authors.initials: L
authors.lastname: De Marco
authors.affiliation: Cancer Epidemiology Unit - C.E.R.M.S., University of Turin, Via Santena 7, 10126 Turin, Italy. Electronic address: gilliotos.demarco@cpo.it.
authors.forename: Anna
authors.initials: A
authors.lastname: Gillio-Tos
authors.affiliation: Venetian Oncology Institute-IRCCS, Via Gattamelata 64, 35128 Padova, Italy. Electronic address: annarosa.delmistro@ioveneto.it.
authors.forename: Annarosa
authors.initials: A
authors.lastname: Del Mistro
authors.affiliation: S. Chiara Hospital, Largo Medaglie d'Oro 9, 38122 Trento, Italy. Electronic address: salvatore.girlando@apss.tn.it.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Girlando
authors.affiliation: Venetian Oncology Institute-IRCCS, Via Gattamelata 64, 35128 Padova, Italy. Electronic address: lorena.baboci@gmail.com.
authors.forename: Lorena
authors.initials: L
authors.lastname: Baboci
authors.affiliation: Cancer Epidemiology Unit - C.E.R.M.S., University of Turin, Via Santena 7, 10126 Turin, Italy. Electronic address: morena.trevisan@matica.eu.
authors.forename: Morena
authors.initials: M
authors.lastname: Trevisan
authors.affiliation: ISPO Cancer Prevention and Research Institute, Via Cosimo il Vecchio 2, 50139 Florence, Italy. Electronic address: e.burroni@ispo.toscana.it.
authors.forename: Elena
authors.initials: E
authors.lastname: Burroni
authors.affiliation: Centre for Cancer Prevention, Via S. Francesco da Paola 31, 10123 Turin, Italy. Electronic address: stefano.grasso@cpo.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Grasso
authors.affiliation: Servizio Interaziendale di Epidemiologia - Azienda Unità Sanitaria Locale and IRCCS, Arcispedale Santa Maria Nuova, Via Amendola 2, 42122 Reggio Emilia, Italy. Electronic address: Paolo.GiorgiRossi@ausl.re.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Giorgi Rossi
authors.affiliation: Centre for Cancer Prevention, Via S. Francesco da Paola 31, 10123 Turin, Italy. Electronic address: guglielmo.ronco@cpo.it.
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Ronco
mesh_terms: D000328:Adult; D052685:Alphapapillomavirus / Q000235:genetics*; D002584:Cervix Uteri / Q000473:pathology / Q000821:virology; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008875:Middle Aged; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000517:prevention & control*; D053918:Papillomavirus Vaccines / Q000276:immunology*; D011159:Population Surveillance; D015995:Prevalence; D002583:Uterine Cervical Neoplasms / Q000453:epidemiology / Q000517:prevention & control / Q000821:virology; D014611:Vaccination
chemical_list: D053918:Papillomavirus Vaccines
keywords: Genotyping; High risk HPV; Human papillomavirus; Vaccine