Comparative efficacy of Berenil and Samorin in albino rats experimentally infected with current field isolates of Trypanosoma brucei brucei

The efficacy of two standard veterinary trypanocides, diminazene aceturate (Berenil-therapeutic) and isometamidium chloride (Samorin-prophylactic) was compared in albino rats experimentally infected with current field isolate of Trypanosoma brucei brucei (Federe strain). The study consisted of forty albino rats, divided into 8 groups of five animals each. The negative control was uninfected and untreated (Group 1), whereas the positive control was infected and untreated (Group 2). Other groups were treated intramuscularly with either 0.5 mg/kg or 3.5 mg/kg body weight of Samorin or Berenil respectively adopting different protocols. Groups 3 and 4 were treated the same day of infection with Berenil and Samorin respectively (treatment was before infection). Groups 5 and 6 were treated at patency (4 days post infection) with Berenil and Samorin respectively. Groups 7 and 8 were infected before treatment on the same day with Berenil and Samorin respectively, and re-challenged with the T.brucei brucei after four days. The results obtained 60 days post treatment showed that the difference between the efficacies of the two drugs was significant (P< 0.05). Berenil cleared the parasites more from the blood of the albino rats than Samorin. From the recorded values of the parameters (body weight, temperature, packed cell volume and parasitaemic profile), it was concluded that Berenil is a more efficacious trypanocide than Samorin, and is recommended as the drug of choice in the treatment of animal trypanosomiasis.Keywords: Laboratory, animal, trypanosomiasis, treatment, trypanocides