Comparison of the effects of Trypanosoma congolense and Trypanosoma brucei brucei on the gross pathology and haematological indices in laboratory rats

Abstract

Trypanosomiasis is considered the most important infectious disease holding back the development of livestock production in Africa. Studies to compare the effects of Trypanosoma brucei and Trypanosoma congolense on some parameters and the impact on some visceral organs of albino rats were carried out. Twelve (12) albino rats were grouped into three groups named A, B and C (four rats per group). Each animal in groups A was inoculated with 0.15ml (about 10⁶) Trypansoma brucei and group B with T. congolense, while group C served as the control. There was significant decrease  (P < 0.05) in packed cell volume (PCV) (range 24.0 - 46.5) and body weight (range 21.9 - 47.0) in the infected whereas body weight progressively increased in the control. There were little temperature changes but the highest increase of 3.20⁰C prior to death was noted in T. congolense infected rats. There was massive rise in parasitaemia (154.919 x 10⁶ and 164.577 x 10⁶) in the T. brucei and T. congolense infected rats respectively before death. Postmortem examination of viscera organs showed marked changes with gross enlargement of liver and weak connective tissue, enlarged spleen, reduced lungs and brain, congested and pale kidney. It is concluded that T. brucei is more pathogenic in albino rats leading to death faster than in T. congolense infected rats which need a higher parasitaemia and the longer infection time.