Detection of Toxoplasma gondii antigens in urine by reverse latex agglutination test during human toxoplasmosis.

T. gondii antigens were detected in concentrated urine samples of 39 out of 40 patients with acute toxoplasmosis and in 38 serum samples of the same patients by the reverse latex agglutination (RLA) test which showed a high sensitivity of 97.5% and 95%, respectively. By capture enzyme-linked immunosorbent assay (ELISA). T. gondii antigens were detected in concentrated urine samples of 30 out of the 40 patients in 29 sera of the same patients, recording a moderate sensitivity of 75% and 72.5%, respectively. T. gondii antigens were not detected in urine or serum samples of patients with chronic toxoplasmosis by neither RLA test nor ELISA. No false positive reaction was observed with urine or serum samples of normal--or other parasitic infection--control individuals, recording a specificity of 100% for each of RLA test and ELISA. Urine samples were collected easily and readily without causing any inconvenience to the individuals enrolled in the study. The RLA test was easy to perform and visually interpreted within 2-3 minutes. The diagnosis of acute toxoplasmosis through the detection of easily obtainable urinary T. gondii antigens by the highly sensitive and specific RLA test is discussed.