Effects of Toxoplasma gondii on human semen parameters and sperm DNA integrity

Objective Toxoplasma gondii(TOX) infection is associated with male infertility. Sperm DNA integrity is an important marker of male fertility. The aim of this paper is to investigate the influence of TOX infection on the human semen parameters and sperm DNA integrity. Methods The recruited infertile patients were divided into TOX-IGG positive group, TOX-IGM positive group, other pathogens infection group and no-infection group. The recruited normal males with normal fertility were included as controls. The differences in semen quality and sperm DNA fragmentation index(DFI) were statistically analyzed between the infertile men and normal controls. The sperm concentration and vitality were analyzed by using computer assisted sperm analysis(CASA), sperm survival rate by using hypoosmotic swelling test, sperm morphology by using Diff-Qick staining, and sperm DNA damage index DFI(%) by using single cell gel electrophoresis(SCGE). Results There were statistically significant differences in semen quality parameters between the control and the infertile groups(P<0.05). Compared with the no-infection group, the rate of progressively motile sperm(PR) in TOX infection group was significantly decreased(P<0.05). The differences in mild DFI, severe DFI and total DFI were statistically significant between the TOX infection groups and normal controls. Compared with the no-infection group, the severe and total DFI in TOX infection group had statistically significant differences(P<0.05), mild DFI in TOX infection group had no significant differences(P>0.05). Compared with the other pathogens infection group, the mild, severe and total DFI in TOX infection group had no statistically significant differences(P>0.05). Compared with the TOX-IGG positive group, the severe and total DFI in TOX-IGM positive group were significantly increased(P<0.01). Conclusion TOX infection could affect human semen parameters and sperm DNA integrity. The degree of damage in new infections was more obvious compared with the past infections.