Objective: To 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.
Methods: Serum 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).
Results: Frequency 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.
Conclusions: It 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.