Comparative bone marrow responses of albino rats experimentally infected with single and mixed species of Trypanosoma congolense and Trypanosoma brucei and ability to control anaemia

J.N. Abenga, S.M. Samd, F.O. Fajinmi, A.M. Kalgo

 

Abstract

Effect of Trypanosoma congolence and T. brucei mixed infection on ability of the bone marrow to respond to anemia was investigated in albino rats. This was with the view of assessing the possible impact on recovery rate from anemia following chemotherapy of African trypanosomosis. The investigation involved descriptive evaluation of packed cell volume and corresponding bone marrow cytological changes associated with single and mixed infection of T. congolense and T. brucei. It involved laboratory based experimental infection of albino rats as research models. A total of 32 adult albino rats of mixed sexes were used for this investigation. The rats were randomly grouped into three groups, A, B, C made up of 8 rats each, and infected with T. congolenseT brucei and mixed infection of these species.. Eight other rats served as the uninfected control group.Parameters measured included weekly packed cell volume (PCV) and differential bone marrow cytology of the different groups of infected and control rats at the end of 21 days post infection (PI). At the end of 21 days PI, the anemia characterized by drop in PCV was most severe in the mixed infection group, and least in T. brucei group with tendency for self-recovery from anemia. The bone marrow responses in the mixed infection group was however weak and inferior to that of T. brucei and T. Congolense groups. Poor erythropoietic response in the mixed infection group despite significant fall (P < 0.05) in PCV level was believed to arise from severe renal and hepatic pathology resulting to subnormal erythropoietin release and severe stem cell injury. This is believed would cause longer time to be taken by mixed infection animals to recover from anemia after chemotherapy. It is concluded that T. congolense and T. brucei mixed infection result to marked incapacitation of the bone marrow and ability for recovery from anemia. This suggests that supportive administration of synthetic erythropoietin may be required in trypanosome specie mixed infection situation due to severe pathological effects on the kidney and liver resulting to impaired erythropoietinbiosynthesis and slow recovery from anemia following chemotherapy in African trypanosomiasis.

Keywords: Anemia, bone marrow, mixed infection, rats, trypanosomiasis, erythropoietin

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Comparative bone marrow responses of albino rats experimentally infected with single and mixed species of Trypanosoma congolense and Trypanosoma brucei and ability to control anaemia

Effect of trypanosoma congolense and Trypanosoma brucei mixed infection on the pattern of haematological changes in murine trypanosmosis

JN Abenga, SA Sands, OGC Ezebuiro

 

Abstract

The effect of Trypanosoma congolense and T. brucei mixed infection on the pattern of haematological changes was demonstrated in a rat model. At the end of 21 days post infection (PI), anaemia which was characterised by drop in the packed cell volume (PCV), was found to be significantly (P<0.05) severer in rats with mixed infection than those infected with T. congolense or T. brucei. Similar pattern of drop in the total white blood cell (WBC), differential WBC, and platelet counts was observed in the group with mixed infection. It was concluded that even though T. congolense and T. brucei may cause milder haematological changes in animals compared to T. vivax, mixed infection by these parasites may cause severer haematological changes in the natural hosts.

Keywords: mixed infections, pattern of haematological changes, rats, Trypanosoma congolense, Trypanosoma brucei

African Journal of Clinical and Experimental Microbiology Vol. 6 (3) 2005: 193-197