Three cases of trypanosomiasis relapsing during treatment with Bayer 205 (Germanin)

Three Africans, infected with Trypanosoma rhodesiense, were treated with Bayer 205. During or shortly after the treatment, i.e., 5, 9 and 19 days respectively after the last dose, relapses occurred, with numerous trypanosomes in the blood, accompanied by a febrile reaction. Although no further treatment was given at the time, the trypanosomes disappeared from the blood in a few days' time, and the pyrexia subsided. Strains of trypanosomes were obtained from two of these patients and tested in rats. No evidence was found of any abnormal resistance to Bayer 205. Chemical estimations of the concentration of Bayer 205 in the blood of these patients at the time of relapse and during subsequent treatment, showed that the accumulation of the compound in the blood was defective as compared with that of patients studied in a previous series. For reasons which are discussed, it is concluded that this defective accumulation was one of the main factors responsible for these relapses. A review of the literature shows that similar relapses have been recorded by many other observers. It is recommended that where possible chemical estimations should be made on the blood of patients receiving Bayer 205, in order to detect the individuals in whom such defective accumulation occurs.