An Assessment Of The Efficacy Of Dfmo In Baboons (Papio Anubis) Infected With Trypanosma Brucei Gambiense

Abstract

Infection of four baboons with Trypanosma brucei gambiense resulted in a prepatent period of 3 – 4 days. Following the first appearance of T. b. gambiense parasitaemia, the animals developed trypanosomosis characterised by elevated parasite counts in the blood, fever, increased heart and respiratory rates and increased capillary refill time. The disease was also associated with pallor of visible mucous membranes, oedema, increased reticulocyte counts, progressive decline in erythrocyte indices (RBC, Hb and PCV), consistent monocytosis, and leucopenia due to
lymphopenia and neutropenia. These clinical signs and widespread pathological changes seen in the liver, kidney, lymph nodes, heart and brain were progressive with the disease. The disease also disrupted the circadian rhythmicity of sleep and wakefulness between weeks 8 and 10 when the animals were in the classical diurnal sleepiness with 8 - 10 sleep episodes and nocturnal restlessness. All the infected baboons died from the attendant disease between the 8 and 10 weeks of infection. Treatment with Berenil or DFMO at 4 weeks post infection reversed most of the clinical, haematological and pathological changes, the CSF-WBC counts and cleared the parasites from the circulation of the infected baboons. However, there was relapse parasitaemia by 18 and 20 weeks respectively post infection in the groups treated with DFMO and Berenil. The results of this study suggest that baboons manifest similar clinical and pathological lesions as man infected with T. b. gambiense and might therefore be a useful model for the study of the human disease. Furthermore, the results suggest the therapeutic usefulness of DFMO in the treatment of human and animal trypanosomosis due to T. b. gambiense.