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.