Age distribution of high-risk HPV infection and cervical lesions in an unvaccinated adult Brazilian population within an organized screening program.

High-risk human papillomavirus (hr-HPV) persistent infection is the necessary cause of cervical cancer, yet age-specific prevalence patterns in unvaccinated adult women remain insufficiently characterized in Brazil. This population-based study describes the distribution of hr-HPV infection and cervical lesions among 20,398 women aged 25–64 years screened during the first screening round of the PREVENTIVO organized program using HPV-DNA testing in Indaiatuba, Brazil (2017–2022). Overall hr-HPV prevalence was 12.8% (95% CI: 12.4–13.1), with a bimodal age pattern: a first peak at 25–26 years (26%) and a smaller second peak at 55–56 years (11.2%). HPV16, HPV18, and 12 other hr-HPV types were detected in 2.63%, 1.01%, and 10.72% of women, respectively, all showing significant age-related declines. Among hr-HPV positive women, 12.4% had CIN2+, including 29 cervical cancers. CIN2 + rates ranged from 11 to 17% between ages 25–49, decreased after, and showed a late HSIL peak at 61 years (8.2%). Cervical cancer peaked at 45–46 years, with no cases after age 55, reflecting the impact of early precursor detection within the program. These findings demonstrate a persistent burden of hr-HPV and high-grade lesions at older ages and provide essential baseline data for monitoring vaccination impact. They also support consideration of extended of screening strategies, including a potential hr-HPV “exit test” beyond age 64.