High occurrence of Toxoplasma gondii infection among blood donors in Ardabil Province as main focus of zoonotic visceral leishmaniosis, northwestern Iran.

Toxoplasmosis, as cosmopolitan parasitic disease, is considered as one of the transfusion-transmitted parasites. The true burden of Toxoplasma gondii (T. gondii) amongst blood donors remains undisclosed around the world. Since there was no evidence on the prevalence of T. gondii in blood donors in Ardabil Province, as main focus of zoonotic visceral leishmaniosis (ZVL), northwestern Iran, current research was therefore conducted to estimate the seroprevalence of T. gondii and PCR assay among them for the first time. In the present study, 462 plasma samples from asymptomatic blood donors of Ardabil Province, northwestern Iran, were tested for IgM and IgG anti-T. gondii antibodies levels using ELISA test. Moreover, the buffy coat of all seropositive subjects was screened for T. gondii DNA by conventional PCR. Also, the data sheet consisting of characteristic information was registered for all the applicants. Overall, anti-T. gondii antibodies were found in 36% (166/462) of asymptomatic blood donors. Anti-T. gondii IgM and IgG seroprevalence was 1.5% and 32.5%, respectively. Only nine subjects (2%) were found to be positive for both IgM and IgG. Moreover, T. gondii DNA was identified in 18% (30/166) of seropositive donors. The logistic regression analysis showed a significant correlation between T. gondii seropositivity and contact with cats, agricultural activities, history of consumption of undercooked meat and being non-educated (P=0.001). The high prevalence (about one-third) of anti-T. gondii antibodies and possibly active infection using conventional PCR test represents that asymptomatic carriers of T. gondii are quite common in the study areas and pose a potential threat to the blood safety and hemovigilance program.