A new modification of the horse erythrocyte agglutination test for the detection of heterophilic antibodies in infectious mononucleosis]

The new modification (HEA test) is based on the presence of a singularly distinct agglutination of native horse erythrocytes in a serum dilution 1:10 and more from cases with Epstein-Barr virus infectious mononucleosis. In 1665 sera the HEA test was equally often positive as the OCH test (in 5.2%) whereas the IM test with formal-treated horse erythrocytes was positive only in 3.7%. The sensitivity of the IM test in comparison with the OCH test was 61%, the specificity 99.5%. The sensitivity of the HEA test in comparison with the OCH test was 76%, the specificity 98.7%. The specificity of the HEA test in a group of 52 sera without IgG antibodies to EB-viral capsid antigen (EB VCA) was 94%, in another group of 130 sera from hepatitis cases it was 98%. In 103 pairs of sera from infants aged 1-5 years the positivity of the OCH test, HEA test, IgM antibodies to EB VCA and the four-fold rise in the titre of EB-viral IgG were, 20%, 16%, 23% and 24% respectively. Analogous values in 159 pairs of sera from older subjects were 42%, 40%, 38% and 29%. The HEA test is recommended as useful adjunct to the OCH test for the detection of heterophile antibodies even in young children.