Abstract:
1. The complement fixation test may be used for the diagnosis of dourine occurring naturally in South Africa, provided T. equiperdum antigen is employed. 2. Animals infected with T. brucei react to the complement fixation test when T. equiperdum antigen is used. 3. Animals suffering from a pure T. congolense infection do not usually react when T. equiperdum antigen is used, though in rare cases a partial reaction may be obtained. In Table 2 it will be observed that cattle 317 and 101 each on one occasion reacted strongly. That this was exceptional is shown by the series of reactions in Table 5. 4. There is some evidence to show that sera obtained from animals with pure T. congolense infections may give marked reactions with T. congolense antigen. The sera of animals infected with T. equiperdum react slightly or not at all to this antigen. 5. The sera of a number of cattle showing pure infections with T. vivax did not give reactions to the complement fixation test using T. equiperdum antigen.
