Frequency of human papillomavirus infection and genotype distribution among women with known cytological diagnosis in a Southern Italian region


Introduction. In the Puglia region (South Italy) about 200 new hospitalizations for cervical cancer are registered every year. The study investigated the frequency of Human Papillomavirus (HPV) infection and the genotype distribution of HPV in a sample of women with known cytology attending the outpatient clinics of four Gynecological Departments of the University of Bari over a four-year period (2005-2008). Methods. Cervical samples from 1,168 women were analyzed for the presence of HPV-DNA through Polymerase Chain Reaction (PCR) in L1 region and reverse hybridization. The cytological results were associated with HPV positivity and type-specific prevalence. Results. Overall, HPV infection was found in 355 (30.4%) women. HPV-DNA was found in 34.4% of women with a cytological diagnosis of ASCUS, in 46.8% of women with Low-grade Squamous Intraepithelial Lesion (LSIL) and in 87.0% of women with High-grade Squamous Intraepithelial Lesion (HSIL)/carcinoma. Also 16.0% of women with normal Pap smear were found to be HPV-DNA positive. The most common HPV genotype was type 16 found in 27.3% of positives, followed by type 53 (11.5%), type 66 (9.2%) and type 31 (9.0%). HPV genotype 18 was found in 6.4% of positives. Types 16 or 18 were detected in about 34% (120/355) of all infected women, in about 33% of LSIL and in 60% of HSIL/ carcinoma HPV-positive women. Among low risk (LR) genotypes, type 61 was found in 10.7% of HPV positive women, type 62 in 8.4%, type 42 in 8.1% and type CP6108 in 7.8%. Discussion and conclusions. The findings of the study give evidence that HPV infection is frequent in the studied cohort of women. The most widespread genotypes found were 16 and 53. These data may represent a benchmark for future evaluation after the recent introduction of vaccination against HPV in 12-year-old girls.