EVALUATION OF VARIANT SPECIFIC TRYPANOLYSIS TESTS FOR SERODIAGNOSIS OF HUMAN INFECTIONS WITH TRYPANOSOMA-BRUCEI-GAMBIENSE

Twelve T.b. gambiense clone populations of distinct Variable Antigen T ype (VAT) were combined in immune lysis tests with 340 sera of trypano some infected patients from 8 different African countries and 267 non trypanosomiasis control sera. The diagnostic specificity of the test w as 100%. At a serum dilution of 1:4 the overall test sensitivity with single VATs varied from 39.1 to 98.2% and from 12.1 to 86.8% at 1:32. At a serum dilution of 1:32 some combination tests with 2 VATs still s cored above 96%. The VAT recognition patterns were clearly correlated with the geographical origin of the sera, reflecting a diversity in va riable antigen repertoires.