THE HAEMAGGLUTINATION TEST FOR TOXOPLASMA ANTIBODIES BY

Four hundred and forty-six patients ' sera from a hospital blood transfusion department in Newcastle were examined for toxoplasma antibodies by a haemagglutination test. Forty per cent. of the sera gave positive reactions, and an increase in the percentage of positive sera was found with increasing age, rising to over 60 % at the age of 70 and over. A wide range of titres was demonstrated amongst positive cases, the highest titres approaching those obtained in two cases of active toxoplasmosis. In a separate survey, no quantitative agreement was found between dye test titres and haem-agglutination titres. As knowledge of toxoplasmosis has increased, efforts have been made to improve and extend the range of specific diagnostic tests. At present, the test most commonly employed is the Sabin-Feldman dye test or one of its modifications. This is tech-nically exacting to perform, and requires the presence of live toxoplasmas, as well as a supply of norma