Research Article

Association Between Trichomonas vaginalis Infection and Semen Quality in Infertile Men: A Retrospective Analysis

Abstract

Background: Trichomonas vaginalis is a common sexually transmitted infection, which was found to impact male infertility through inflammation and oxidative stress-mediated sperm impairments. Objective: To investigate the effect of T. vaginalis infection on semen quality, inflammatory semen findings, oxidative stress markers, and sperm DNA fragmentation. Methods: A retrospective case-control study included 150 infertile men and 150 fertile controls. T. vaginalis infection was diagnosed by PCR, and semen parameters were compared between infected and uninfected men. Inflammatory semen indicators of leukocytospermia, viscosity, liquefaction status, and semen culture positivity were extracted from laboratory records. Oxidative stress markers were investigated through measuring reactive oxygen species (ROS) with fluorometric ROS assay (DCFH-DA), malondialdehyde (MDA) with thiobarbituric acid reaction, and sperm DNA fragmentation with TUNEL assay. Results: Prevalence of T. vaginalis among in infertile men was found higher than fertile controls (18.0% vs 4.0%, p < 0.001). Infected men also showed lower semen volume (2.2±0.9 vs 2.5±0.7 mL, p=0.040), lower concentration (30.5±13.4 vs 54.3±20.7 million/mL, p < 0.001), lower total sperm count (72.4±33.1 vs 135.6±57.2 million, p < 0.001), reduced progressive motility (26.8±9.5% vs 46.2±12.3%, p<0.001), total motility (38.6±11.4% vs 58.9±14.6%, p<0.001), morphology (2.9±1.3% vs 5.1±2.0%, p=0.015), and vitality (55.4±10.2% vs 69.8±11.5%, p=0.024). Cases with leukocytospermia, higher viscosity, delayed liquefaction, and positive semen culture were more frequent in infected men (all p<0.05). ROS, MDA, and DNA fragmentations were markedly higher in the infected group (all p≤ 0.01). Conclusion: T. vaginalis infection was strongly associated with altered semen characteristics accompanied by higher inflammatory and oxidative stress-related sperm damage.