ISOLATION AND CHARACTERIZATION OF A NEW SERODEME OF TRYPANOSOMA-RHODESIENSE

Isolation and characterization of a new serodeme of T. b. rhodesiense is described. A clone of organisms derived from a human infection produced chronic infections in mice. Additional clones of differing antigenic specificities were isolated from peaks of parasitemia which occurred in these mice. Variable antigen types (VAT) of these clones were determined by agglutination, immunofluorescence and protection of actively immunized mice. Thirteen distinct VAT were isolated and designated Walter Reed Army Trypanozoon antigenic types. The described methodology and reagents and chronicity of the infection produced in mice by this serodeme provide a model for further study of immunopathology and antigenic variation in African trypanosomiasis. Use of these reagents in determining incidence of VAT in an endemic area may allow assessment of the feasibility of immunoprophylaxis.