Do we need to screen Egyptian voluntary blood donors for toxoplasmosis?

ObjectiveTo determine the value of voluntary blood donors screening in diagnosing asymptomatic toxoplasmosis in an attempt to reduce the risk of this infection in Egyptian immunocompromised recipients.MethodsSerum samples from 300 healthy voluntary blood donors were analyzed for anti-Toxoplasma antibodies [immunoglobulin G (IgG) and immunoglobulin M (IgM)] using ELISA and detection of Toxoplasma gondii (T. gondii) parasitemia was done by real-time quantitative PCR (qrtPCR).ResultsFrequency of T. gondii infection in 300 healthy blood donors was 101 (33.67%), 10 (3.33%), 18 (6.00%) by ELISA IgG, IgM and qrtPCR, respectively. It was found that 8 of 18 (44.4%) donor samples positive by qrtPCR contained IgM anti-T. gondii, conversely 8 of 10 (80%) IgM-positive samples were positive for T. gondii DNA. There was a highly significant increase in detection of recent Toxoplasma infection using PCR over IgM ELISA by 55.6%. At the same time, T. gondii parasitemia was detected in 11 of 101 (10.90%) donor samples positive by IgG ELISA and in 7 of 199 (3.50%) negative donor samples for anti-T. gondii IgG antibodies. On the other hand, the negative results obtained by both qrtPCR and ELISA in 192 (64%) subjects ruled out the infection in those donors.ConclusionsIt might be appropriate to include the screening of blood and blood products for T. gondii in the pre-transfusion blood testing schedule in Egypt. Also, molecular screening should be carried out on the blood being transfused to immunocompromised patients.