Acute and chronic effects of Trypanosoma brucei brucei experimental infection on bone marrow and peripheral blood cells in Wistar rats

Peripheral and bone marrow cell changes due to Trypanosoma brucei brucei infection were studied in forty (40) adult male wistar rats weighing 200 ± 50g. Thirty (30) rats were infected intraperitoneally with Trypanosoma brucei while ten (10) uninfected rats served as control. At the acute stage of 6 days post infection (dpi) and chronic stage of 15 dpi, blood samples were obtained. Haematological investigations on the samples included Packed Cell Volume (PCV), Haemoglobin Concentration (Hb), Red Blood Cell Count (RBC), White Blood Cell Count (WBC), Platelet Counts, Reticulocyte Counts, Mean Cell Volume (MCV), Mean Cell Haemoglobin (MCH), Mean Cell Haemoglobin Concentration (MCHC) and Myeloid-Erythroid (M:E) ratio estimation of bone marrow cells. At the acute stage, there was significant (P<0.05) decrease in PCV, Hb, RBC and Platelet count while WBC and Reticulocyte Count increased when compared to control. During the chronic stage, PCV, Hb, MCV and platelet count decreased (P<0.05) while increases were recorded for WBC, RBC and reticulocyte counts compared to control values. Myeloid erythroid (M:E) ratio changed from 3:1 to 3:3 but bone marrow cells were hypochromic, with increased erythroid cell population and giant macrophages. It was observed that hypochromic microcytic anaemia, thrombocytopaenia, leucocytosis (as a result of lymphocytosis and eosinophilia) and reticulocytosis are the most important haematological changes associated with infection of Trypanosoma brucei bucei in rats