Antigenic variation in Trypanosoma evansi: variable antigen type development in mice, sheep and goats.

The early VAT development of a stock of Trypanosoma evansi was studied in mice, sheep and goats. Host species did not appear to influence the range of VATs which were detected early in infection, although differences were seen in the VAT composition of individual trypanosome populations isolated at similar periods after infection in the different hosts. Ten VATs, previously classed as predominant VATs from studies on T. evansi-infected rabbits, were also found to act as predominant VATs in sheep and goats. These 10 VATs were also found in first relapse populations from mice infected with this stock of T. evansi. Such relapse populations could serve as a source of predominant VATs for serodeme analysis of stocks of T. evansi.