A study of the antigenic relationships of isolates of Trypanosoma brucei from three areas in East Africa.

Eleven stabilates of T. brucei, prepared from isolates collected from cattle and tsetse flies in three areas of East Africa, were compared serologically by direct agglutination tests, using (a) stabilate-specific antisera prepared in rats and (b)antisera to the predominant variant antigens of each isolate prepared in rabbits. The results indicated that groups of isolates from any one area tended to produce antigens in common, whereas isolates from different areas were generally antigenically distinct. The comparison of isolates of T. brucei on the basis of their predominant variant antigens, as a technique, was more simple to effect, and more sensitive in the detection of antigenic relationships, than comparison founded on basic strain antigens.