Pleomorphism and the problem of recrudescent parasitaemia following treatment with salicylhydroxamic acid (SHAM) in African trypanosomiasis.

The curative action of a single dose of salicylhydroxamic acid (SHAM) in combination with glycerol was investigated in mice infected with a variety of monomorphic and pleomorphic African trypanosomes. The treatment of mice infected with monomorphic members of the sub-genus Trypanozoon was always successful and resulted in a complete cure. Treatment of animals with pleomorphic infections resulted in an initial clearance of the parasitaemia which later recrudesced. Both chronic and acute infections with Trypanosoma vivax were radically cured with SHAM plus glycerol, while infections with T. congolense and T. musculi were never cured.