Association between Trichomonas vaginalis infection and cervical lesions: a population-based, nested case-control study in Taiwan

Trichomonas vaginalis is the most common nonviral sexually transmitted infection. According to the 2019 WHO cancer report, cervical cancer is the fourth most frequent cancer in women. However, previous research, which has not included a large-scale study to date, has revealed that Trichomonas vaginalis increases cervical cancer risk. In this study, we investigated a group of Asian females in Taiwan to determine the association between trichomoniasis and the risk of developing cervical lesions, including cancer, neoplasm, and dysplasia. We conducted a nested case-control study by using the National Health Insurance (NHI) program database in Taiwan. The International Classification of Diseases, 9th Revision classifications (ICD-9-CM) was used to categorize all of the medical conditions for each patient in the case and control groups. The adjusted odds ratio (AOR) and 95% confidence interval (CI) for the association between trichomoniasis and cervical lesions were estimated using multivariable conditional logistic regression to adjust for all comorbidities and variables. In total, 54,003 individuals were enrolled in the case group and 216,012 were enrolled in the control group. Trichomonas vaginalis exposure had a significant association with cervical lesions (AOR 2.656, 95% CI = 1.411–5.353, p = 0.003), especially cervical cancer (AOR 3.684, 95% CI = 1.622–6.094, p = 0.001). In patients with both trichomoniasis and depression, the relative risk increased 7.480-fold compared to those without trichomoniasis or depression. In conclusion, female patients with Trichomonas vaginalis exposure had a significantly higher risk of developing cervical lesions (especially cervical cancer) than those without exposure.