Epidemiological profile of HPV infection, associations with cervical lesions and vaginal microecological disorders, and nine-valent vaccine coverage in Northwest China: a 6-year retrospective study of 57,035 women

Cervical cancer is a leading cause of female cancer mortality globally, with a rising burden in China. Persistent high-risk human papillomavirus (HR-HPV) infection is the established driver of cervical carcinogenesis, but regional epidemiological data and associations between HPV and vaginal microecological disorders remain poorly characterized in Northwest China. We conducted a retrospective study of 57,035 female outpatients at a tertiary hospital in Shaanxi Province from 2016 to 2021. HPV genotyping was performed to assess persistent infection patterns, 9-valent vaccine coverage across three cervical lesion risk strata, and correlations with bacterial vaginosis (BV), aerobic vaginitis (AV), trichomonal vaginitis (TV), and vulvovaginal candidiasis (VVC). In this study of 57,035 female outpatients undergoing HPV genotyping, the overall HPV positivity rate was 28.77%, with infections dominated by isolated high-risk HPV (HR-HPV) and single-genotype patterns. HPV16, 52, 58, 53 and 51 were the most prevalent HR-HPV genotypes, and HPV prevalence showed a bimodal age distribution peaking at 26–30 years with a secondary peak at ≥ 61 years. Among 3,542 patients with follow-up, the overall persistent infection rate was 33.75%, highest in mixed HR/LR-HPV infections. HPV positivity correlated with elevated abnormal TCT rates, and nine HR-HPV genotypes were significantly associated with cytological abnormalities; HPV16 accounted for 69.7% of cervical cancer cases. The coverage of 9-valent vaccine genotypes increased with disease severity. HPV infection was positively associated with bacterial vaginosis, trichomoniasis and mixed vaginitis, but inversely linked to vulvovaginal candidiasis, with subtype-specific association patterns. This study provides comprehensive regional HPV epidemiological evidence and reveals subtype-specific HPV-vaginal microecology interactions, supporting tailored cervical cancer prevention strategies in Northwest China.