Prevalence and type distribution of high-risk human papillomavirus infection in women undergoing voluntary cervical cancer screening in Italy

Abstract

The aim of this survey was to assess the prevalence and distribution of oncogenic human papillomavirus (HPV) genotypes in women who underwent screening for cervical cancer in Italy. The correlation of genotypes with the cytological results was also evaluated. Cervical samples were collected from 9,947 self-referring women for cervical cancer screening. Participants were screened by liquid-based cytology and high-risk HPV testing using the Hybrid Capture 2 test. Positive samples were genotyped by PCR. Samples (1,474; 14.8%) were positive for high-risk HPV. The prevalence was 29.4% in the 15-19 years-group, decreasing progressively to 6.1% at 50-54 years of age and increasing to 12.2% in those aged over 65 years. HPV 16 was the genotype detected most frequently followed by HPV 31, HPV 18, HPV 56, and HPV 51. HPV 16 or 18 were present in 4% of women with normal cytology and both were detected contemporarily in only 14 women. Twenty-two percent of atypical squamous cells, 26% of low-grade and 56% of high-grade squamous intraepithelial lesions at cytology were positive for HPV 16 and/or 18. The prevalence of HPV infection in Italy is in agreement with that reported worldwide. HPV 16 was the prevalent genotype. The concomitant infection with HPV 16 and HPV 18 (vaccine targets) was found rarely. Apart from HPV 16 and 18, there was a substantial presence of HPV genotypes against which the vaccines available currently have shown cross-protection efficacy. The findings of this study may contribute to reliable predictions on the potential efficacy of an HPV vaccine in clinical practice.