Comparisons of antigenic types of Trypanosoma (T)brucei strains transmitted by Glossina m. morsitans.

A modified infection and maintenance procedure for the cyclical transmission of T. (T.) brucei in Glossina m. morsitans is described which produced high mature infection rates in the flies. Freshly extruded metacyclic forms and bloodstream forms were serologically typed, using the indirect fluorescent antibody test (IFAT) and the neutralization infectivity test (NIT). Metacyclic forms of a certain strain and its cloned derivative were antigenically homogenous and of the same antigenic type, whereas metacyclics of different strains were antigenically different. Antigenic variation had occurred in bloodstream forms of mice harvested 36 h after the infectious bite.