Seroprevalence and molecular diagnosis of Toxoplasma gondii infection among blood donors in southern Iran

Introduction: Toxoplasma gondii is a protozoan parasite which can be transmitted to human through a variety of routes including blood transfusion. This cross sectional study aimed to evaluate the seroprevalence of Toxoplasma infection and related epidemiological features among healthy blood donors. Methodology: A total of 1,480 healthy blood donors from five blood service centers in Fars province were analyzed for anti-Toxoplasma antibodies. Blood samples were tested for anti-T. gondii IgG and IgM antibodies by enzyme immunoassay. IgM-positive samples were also tested for the presence of Toxoplasma DNA by Polymerase Chain Reaction (PCR). Demographic characteristics of participants were also recorded during samples collection. Results: Anti T. gondii antibodies were detected in sera of 286 out of 1,480 blood donors corresponding to an overall seroprevalence of 19.3% in this population. From these, 182 (12.3%) were seropositive only for IgG, 81 (5.47%) were seropositive only for IgM and 23 (1.6%) were positive for both IgG and IgM. PCR detected active parasitemia in two (1.9%) of the IgM-positive subjects. Age, place of residence and level of education were statistically significant (p < 0.05) with seropositivity to Toxoplasma. Conclusions: Our results highlighted that asymptomatic blood donors, especially those with active parasitemia, may constitute a significant risk of transmitting toxoplasmosis to susceptible recipients.