Background and Objective: Toxoplasma gondii is one of the most important opportunistic parasites and can lead to acute toxoplasmosis in immunocompromised patients. Due to the specific conditions of dialysis patients, this parasite may have different clinical features when compared to other individuals. Given the vulnerability of these patients and lack of information on this subject in Zanjan and Mazandaran, this study was performed on dialysis patients in these two provinces.

Materials and Methods: 280 patients with renal failure undergoing hemodialysis were studied. Their personal information was recorded with questionnaires while blood samples were collected and sera were isolated and subjected to anti-Toxoplasma antibody evaluation using ELISA technique.

Results: The patients included 156 men (55.7%) and 124 women (44.3%). Anti-Toxoplasma IgG was positive in 232 patients (82.9%). The sero-positive ratio of patients in Mazandaran was higher than that of Zanjan (P <0.05). There was no significant association between infection rate and other variables such as location of residence, duration of dialysis, age and gender. Anti-Toxoplasma IgM, indicative of possible acute toxoplasmosis, was also detected in 16 patients (5.7%), all of whom were men from the Mazandaran province.

Conclusion: The study showed that Toxoplasma seroprevalence (indicative of parasite existence in their body) in patients undergoing hemodialysis in the study areas is high. Considering the particular circumstances of dialysis patients and the possibility of reactivation of this parasite from its chronic phase to its acute phase, regular screening for anti-Toxoplasma antibodies in this group of patients is recommended.