Pathobiochemical mechanisms involved in the control of the disease caused by Trypanosoma congolense in African grey duiker (Sylvicapra grimmia)

The course of Trypanosoma congolense infections in African grey duiker (Syl vicapra grimmia) and sheep and goats were studied. Several parameters sugge sted that the grey duiker was much more resistant to trypanosomosis than sh eep and goats. They showed increases in weight during infection, had a much longer pre-patent period, and their peak parasitaemia levels were about 10 0-fold lower than those of sheep and goats. Parasites were no longer detect ed in grey duiker blood 35 days after infection. Anaemia, measured as drops in packed cell volume (PCV), haemoglobin (Hb) concentration and erythrocyt e (RBC) counts were not observed in the grey duiker. In contrast, sheep and goats suffered severe weight losses and had continuously high parasitaemia levels. Sheep and goats developed progressively severe normocytic normochr omic anaemia and leucopenia from day 14 post-infection onwards. Serum levels of total protein, globulin and albumin of grey duiker did not change significantly throughout the course of infection, while the levels o f total serum protein, globulin and gamma -globulin exhibited significant i ncreases from day 21 post-infection onwards in sheep and goats, with peak v alues recorded on 28 and 35 days post-infection in sheep and goats, respect ively. There were inconsistent variations in albumin levels in sheep and go ats throughout the course of infection. There were no significant changes in erythrocyte activities of AST and ALT, while there were transient but significant elevations of ALP level on day 35, and GGT levels between 14 and 35 days post-infection in grey duiker. Co nversely, the levels of all the enzymes were progressively depressed, espec ially from 14 to 49 days post-infection. In vitro erythrocyte peroxidation remained relatively unchanged throughout the period of the experiment in the grey duiker, except for slight but sign ificant increase on day 42 post-infection.