PREPARATION OF TOXOPLASMA ANTIGEN FOR DIRECT AGGLUTINATION TEST AND ITS EVALUATION FOR DIAGNOSIS OF TOXOPLASMOSIS

Abstract

Direct agglutination test (DAT) is a sensitive and simple method, which is applicable in field and unequipped laboratories. In order to evaluate DAT in the diagnosis of Toxoplasma infections, the antigen was prepared in the Protozoology Unit, School of Public Health and it was used in the following studies. a- 251 serum samples collected from suspected toxoplasmosis out-patients were examined for Toxoplasma antibodies by DA and indirect fluorescent antibody (IFA) techniques. Sensitivity and specificity of DAT in comparison with IFAT were computed 83.2% and 76.4% respectively. b- For the comparison of DAT and Parasitology procedures, 31 mice were experimentally inoculated by T. gondii an avirulent strain. After 6 to 8 weeks the experimentally infected mice and the control group were gradually killed and their sera were tested by DA for Tosoplasma antibodies and their brain's tissue for Toxoplasma tissue cyst. All of the sera obtained from the inoculated mice were positive by DAT in titers of >=1:540, and in the wet mount samples of their brains Toxoplasma tissue cysts were also observed. c- 293 serum samples from ruminants (183 sheep, 16 goats and 94 cattle) were examined for Toxoplasma antibodies by DA. Consequently 57 sheep (31.0 %) 4 goats (25.0%) and 32 cattle (34.0%) were seropositive in titer of >=1:40.