The resistance of Trypanosoma congolense, T. vivax and T. evansi to human plasma.

Tests were made in mice on the resistance of cattle trypanosomes to human plasma. 12 stocks of Trypanosoma, congolense were tested' three were fully resistant, eight were moderately or highly resistant, and one was fully sensitive. Four stocks of T. vivax were tested; two were fully resistant, one was somewhat resistant, and one was highly sensitive. Two stocks of T. evansi were tested; both fully sensitive. The possibility is discussed that T. congolense and T. vivax might produce transient infections in man.