The treatment of sleeping sickness (mainly due to trypanosoma rhodesiense) with melarsoprol

1) Out of 61 patients with T. rhodesiense sleeping sickness, who had not been treated previously with melarsoprol, 55 (90 per cent.) were cured. Three relapsed (5 per cent.) and three died (5 per cent.) during treatment. Of these three relapses, one was cured by melarsoprol and nitrofurazone; one relapsed repeatedly after treatments with melarsoprol, mel W and nitrofurazone and died; another, possibly with a T. gambiense infection, has relapsed repeatedly and is still being followed. 2) Confirmation has been obtained that a relapse may sometimes be cured by a second course of melarsoprol. Afterwards a cure is unlikely as melarsoprol resistance of the trypanosome increases sharply. This sharp increase in resistance has been demonstrated by the examination in mice of strains isolated serially in a refractory case.