Human papillomavirus distribution in women with abnormal pap smear and/or cervical intraepithelial neoplasia in vaccination era. A single‐center study in the north italian population

Time trends prevalence of human papillomavirus (HPV) genotypes including negative and untypable infections were analyzed during a 15‐year period (2005–2019) among 5807 subjects with abnormal pap‐smears and/or cervical intraepithelial neoplasia (CIN). The rates of HPV16 dropped by 13% every 3 years (Prevalence Ratio, PR = 0.87, 95% CI = 0.82–0.93) in the CIN1 biopsy, while HPV16 status was unchanged over time in the CIN2+ biopsy. In CIN1 lesions, there was a corresponding increase of HR‐HPV types unrelated to nonavalent vaccine. The rates of HPV 18, 31, and 52, decreased by 35% (PR = 0.65, 95% CI = 0.54–0.79), 19% (PR = 0.81, 95% CI = 0.73–0.91), and 21% (PR = 0.79, 95% CI = 0.73–0.86) every 3‐year interval in CIN2+, respectively. Overall, the prevalence of negative/untypable HPV specimens in the entire database increased from 9.6% (129/1349) in the period 2011–2013 to 17.6% (161/913) and 28.4% (224/790) in the 2014–2016 period and in the 2017–2019 period, respectively (PR = 1.69,95% CI = 1.52–1.88). HPV 16 prevalence decreased significantly among subjects with low‐grade cervical squamous lesions. A significant increase of both HPV types unrelated to nonavalent vaccination and negative/untypable HPV infections was re-ported. The prevalence of HPV types among subjects with abnormal pap smears in Northern Italy is changing. Many variables including demographic factors and possibly vaccination could be responsible for this modification.