Antigenic variation in Trypanosoma evansi. Isolation and characterisation of variable antigen type populations from rabbits infected with a stock of T. evansi.

A cloned stock of T. evansi was shown to undergo antigenic variation giving rise to 11 antigenic variants during the first 30 days of infection in rabbits. Ten of the 11 variable antigen type (VAT) populations isolated during this study were shown to represent predominant VATs of the stock as each of these 10 VATs was shown to develop early in infection in rabbits infected with different VATs of the stock. The probability, therefore, exists that stocks of T. evansi can be classified into VAT-serodemes on the basis of their predominant VAT repertoires for use in epidemiological studies.