Evaluation of Toxoplasma indirect haemagglutination test, Tox HA test 'Wellcome'
Kobayashi, S.; Takeuchi, T.; Tanabe, M.; Miura, S.; Kaneda, Y.; Asami, K.
Japanese Journal of Parasitology 285: 363-370
An indirect hemagglutination test kit for Toxoplasma, Tox HA Test (Wellcome), was evaluated in several respects and compared with the dye test (DT) and latex agglutination test (LA). A qualitative and a quantitative comparison of Tox HA Test with DT and LA exhibited a high agreement of Tox HA Test with these established serological tests, i.e., 97.5% qualitative agreement between Tox HA Test and DT and 96.7% between Tox HA Test and LA with 244 samples of human serum. Titers obtained by Tox HA Test were 4 and 2 times as high as those by DT and LA, respectively. In experimental kitten toxoplasmosis, Tox HA Test exhibited 1:64 on day 15-18 after oral infection with cysts of Toxoplasma and 1:256 or more from day 32-43, indicating a good agreement with DT and LA titers, although DT became positive a little earlier than Tox HA Test. Titers by Tox HA Test were not affected by a concomitant presence of a foreign antibody as determined with sera of SLE systemic lupus erythematosus patients. A non-specific agglutination was not observed with these sera. A study on reproducibility of Tox HA Test gave constant titers as far as tested with serum samples prepared by 4-fold dilutions. A quantitative comparison of 3 different lots of Tox HA Test showed a good agreement, i.e., 88.1-98.3% agreement. Tox HA Test is easy to handle and specific and sensitive enough to be utilized for serological diagnosis of human toxoplasmosis.