Cervical Cytology-Based Screening Identifies Trichomonas vaginalis as a Significant Correlate of Non-16/18 High-Risk Human Papillomavirus Infection in High-Altitude Tibetan Agro-Pastoral Communities: A Cross-Sectional Study of 62,657 Women.

Background: The epidemiological relationship between Trichomonas vaginalis (TV) and high-risk human papillomavirus (HR-HPV) remains controversial in high-altitude populations.

Methods: This was a cross-sectional analysis of 62,657 asymptomatic women from China's Cervical and Breast Cancer Screening Program in Tibetan agro-pastoral communities (2019-2024). TV was microscopically identified through microbial evaluation via Pap smear in cervical cytology; HR-HPV genotypes were detected using commercial kit. Statistical analyses included χ² tests, odds ratios (ORs) with 95% confidence intervals (CIs), and age-stratified comparisons.

Results: The TV prevalence was 1.32%, whereas HR-HPV affected 8.93% of the participants, with the former being dominated by non-16/18 genotypes (81.04-89.13%). TV showed an inverted U-shaped age distribution (peak: 40-49 y, 1.83%); HR-HPV exhibited a U-shaped curve (peaks<20 y/≥60 y). TV-positive women had elevated HR-HPV risk (OR=1.28, 95% CI: 1.03-1.59), with a stronger association for non-16/18 genotypes (OR=1.41, 95% CI: 1.12-1.78); this relationship was most pronounced in women aged 30-49 years (OR=1.30-1.33).

Conclusion: TV infection is significantly associated with non-16/18 HR-HPV in Tibetan women aged 30-49 years, suggesting a potential cofactor role. This association requires cautious interpretation due to unmeasured factors, with future studies needed to clarify these influences.