In human
African trypanosomiasis (HAT), the parasites invade the central nervous system (CNS), leading to the development of meningo-
encephalitis and an irreversible demyelinating process, which kills the patient unless specific treatment is undertaken. Among the experimental
trypanocides, the
nitroimidazole derivative
megazol alone at optimal doses does not cure late-stage disease tested in mouse models, however the combination of
suramin and
megazol is able to cure infected mice without CNS involvement. We recently developed an experimental model of HAT with a sharp decrease in both the food intake and the
body weight which may constitute an effective index of the early meningo-encephalitic phase. Using this model, we tested this hypothesis by the exclusive effectiveness of a
megazol and
suramin combination treatment to eliminate CNS trypanosomes. Sprague-Dawley rats were infected with Trypanosoma brucei brucei AnTat 1.1E. Food intake and
body weight were measured daily from the day of
infection to death. Haematocrit was measured twice a week. Treatment consisted of 20 mg
suramin per kg
body weight administered intraperitoneally (i.p.) alone, or three daily doses (80 mg/kg) of
megazol given per os, or
suramin (20 mg/kg, i.p.) followed 24 h later by three daily doses (80 mg/kg) of
megazol given per os. Treatment was followed by an increase in daily
body weight and food intake similar to those of the control animals, 2 weeks
after treatment. The anaemia developed after
infection is also cleared as shown by the haematocrit measurements. The rats treated with
megazol alone died about 29 days
after treatment and those treated with
suramin, after about 26 days. Seven months later, no signs of relapse were seen in 10 of 12 rats treated with the therapeutic combination, indicating that this
chemotherapy regimen was curative. The results support our previous finding, i.e. the decrease in
body weight may constitute a diagnosis index of the early meningo-encephalitic phase.