An immune adherence hemagglutination (IAHA) test has been developed for the rapid detection of antibodies against Toxoplasma gondii. This test, which utilizes human type 0 erythrocytes and Toxoplasma organisms fixed in formaldehyde solution, is easy to perform, safe, and sensitive. Like the Toxoplasma dye test, the IAHA reaction detects antibodies to surface antigens of Toxoplasma. Unlike the Toxoplasma dye test, the procedure does not require the continuous maintenance of living parasites.
Sera from 80 patients presumed to have toxoplasmic retinochoroiditis and from two rabbits with established Toxoplasma infections were tested by the dye test, the standard hemagglutination (HA) test, and the IAHA test. While there was good general agreement of results in all three tests, the results of the IAHA test correlated more closely with those of the dye test than with those of the standard HA test.
Shimada K, O'Connor GR. An Immune Adherence Hemagglutination Test for Toxoplasmosis. Arch Ophthalmol. 1973;90(5):372-375. doi:10.1001/archopht.1973.01000050374007