Preliminary Report on the Effects of Varied Diminazene Diaceturate Dosages and Treatment Regimens on Trypanosoma brucei Clearance and Relapse in Experimentally Infected Wistar Rats

Abstract

Comparison of the diminazene diaceturate (DD) varied treatment regimen in male Wistar rats experimentally infected with Trypanosoma brucei was done. Forty-nine rats were randomly assigned to seven groups of seven rats each (A – G). Group A was the uninfected untreated control while groups B – G were infected with 1.4 × 106. Groups C and D were treated with 3.5 mg/kg DD once and for five consecutive days while group B was left untreated. Groups E and F were treated with 7 mg/kg DD once and for five consecutive days while group G was treated with 7 mg/kg DD and repeated after 14 days. The effect of varied doses and treatment regimen was evaluated using parasites clearance and relapse of infection. Parasitaemia was established 4 – 9 days post infection in all groups except for one rat in Group G. Trypanosomes were cleared 3 – 5 days post treatment (PT) in all the treated groups. Trypanosomes relapsed in groups C, D, E, F, and group G on days 14, 42, 25, 56, and 39 post treatment, respectively. Relapse also occurred in about 67% of the rats in Group D and 14% of the rats in Group F within 80 days post treatment (PT). Increasing the dosage and or extending the duration of treatment with DD, marginally delayed the clearance of parasite in the infected rats but delayed the onset of relapse and reduced its occurrence in the infected rats. The curative efficacy of DD in this study appeared to be dose dependent as increasing the dosage and duration of treatment elicited a better therapeutic outcome. However, further experimental trials are imperative in rats and other animal species..