Toxoplasma gondii in Saudi blood donors a serological study using three tests.

A total of one hundred and fifty Saudi blood donors were examined for Toxoplasma gondii antibodies (IgG-IgM) by three serological techniques, 50 normal cross matched controls were subjected to the same examination. The number of positive donors for IgG by Indirect Haemagglutination test (IHA) was 36 (24%), by Enzyme Linked Immunosorbent Assay (ELISA) was 70 (46.7%), and by Immunofluorescent test (IFAT) 74 (49.3%). As to IgM the ELISA and IFAT showed 3 positive cases among the blood donors (2%). Rheumatoid factor and antinuclear antibodies were done for positive cases, and showed no significant cross reaction, IgG antibodies were significantly high in donors than in controls. The three tests were more or less dependable. However regarding simplicity, specificity, accuracy and time consumption factor IFAT was recommended for Toxoplasma IgG for all blood donors to avoid the risk of in infection.