Toxoplasmosis: sperm parameters and testosterone levels in men

Toxoplasma gondii is an obligate intracellular parasite that infects more than a third of the world's population. This parasitic protozoan can be replaced in different parts of the female and male reproductive system. Toxoplasmosis has caused changes in the function of sperm, testes, epididymis and prostate, in experimental models. Human studies have investigated the frequency of anti-T. gondii antibodies mostly in the female population, and there is little information about the relationship between this infection and sperm factors and testosterone. This cross-sectional study involved 197 male volunteers who referred to the Fertility and Infertility Research Centre of Hamadan, Hamadan, Iran, from April to December 2023. Sera and semen were collected. ELISA test was performed to detect IgG and IgM antibodies in sera. Semen analysis was carried out based on WHO guidelines. The frequency for anti-T. gondii IgG antibody was detected 48% (95 out of 197). Three percent of participants had anti-T. gondii IgM. The highest level of T. gondii IgG antibodies was observed in the age range of 36 to 40 (p < 0.001). The participants with defects in spermatozoids including abnormal morphology and non-progressive sperms had higher percentage of antibodies against T. gondii (49.1%). Testosterone on average showed normal diversity 540 ng/dl. Fifty-one-point five percent, 48.5%, 52% and 100% of rural, self-employed, smokers and pet-(cat) keeper participants were positive for toxoplasmosis respectively. Although no significant relationship was observed between any other factors except age and toxoplasmosis, it seems that the high frequency of anti-T.gondii IgG in this group of men who have infertility problems confirmed the parasite as not a main factor but a side factor with the production of pro-inflammatory substances as wells as cytokines which can lead to infertility and dysfunction of sperms.