In vivo assessment of drug sensitivity of African trypanosomes using the akinetoplastic induction test.

Following treatment of mice infected with Trypanosoma congolense or T brucei brucei with various doses of isometamidium chloride or diminazene aceturate, the induction of akinetoplastic (AK) forms was observed in the trypomastigotes of both species within 10 hours of drug administration. The levels of AK-induction were closely correlated with the levels of resistance to each compound found using a standard in vivo drug assay in mice. In general, ineffective doses of either compound conferred AK-induction rates of less than 30 per cent; relapsing cases had between 30 and 50 per cent while curative doses had AK-induction rates of 50 per cent or more. In vivo determination of AK-induction rates using ordinary light microscopy is thus a potentially feasible alternative indicator to the conventional use of mice infection and treatment methods for assessing drug sensitivity in African trypanosomes.