Essay --

CHAPTER TWO 2.0 OVERVIEW OF THE DESCRIPTION, LIFE CYCLE OF TRYPANOSOME 2.1. Cell Structure of Trypanosome Trypanosomes are unicellular protozoan having a single flagellum that contains microtubules in the 9+2 arrangement typical of other flagella. At the base of the flagellum, the kinetoplast is found which contains DNA in the form of about 6000 connected circles. The kinetoplast DNA is 10% of the total cellular DNA where the action of some anti-trypanosome drugs occurs such as ethidium. The kinetoplast is part of the single long mitochondrion which undergoes structural changes during various stages of life cycle. The surface of the bloodstream form trypanosome contains a dense coat of variable surface glycoproteins (VSGs) which is replaced by an equally dense coat of procyclins when the parasite segregate into the procylic form in the tsetse fly midgut (Ogbadoyi et al., 2000). Trypanosome brucie a flagellated protozoan, is the causative parasite of the infectious disease known as African trypanosomiasis (African sleeping sickness) in African, while in America, Trypanosoma cruzi causes Chagas disease which is prevalent to human and animal, both are fatal when left untreated (Brun et al., 2010; Carlier et al.,2003; Pereira et al., 2011). African trypanosomiasis is the prominent causes of death in the 36 countries of sub-Saharan African at about 70,000 deaths yearly (Barrett et al., 2003; Keith, 2005). There are two subspecies of trypanosoma brucei that causes sleeping sickness to human which are Trypanosoma brucei gambiense, Trypanosoma brucei rhodesiense while African animal trypanosomiasis or nagana disease is caused by T. congolense, T. vivax and Trypanosoma brucei brucei . Trypanosoma brucei brucei is not infective to ... ...vade immune response) that occur in trypanosome. Thus, persistent infection in the host results to continuity in cycle of trypanosome replication, immune complex development, and changing surface coat glycoprotein (Taylor and Authie, 2004; Sinshaw et al., 2006). The clinical signs of AAT are an intermittent fever, signs of anemia, lymphadenopathy, anaemia, anorexia, dullness, inactivation, depression, loss of milk and meat production, and death in un-treated cases and weight loss. In the pathogenesis of trypanosomiasis, immunosuppression is the most important and complicating factor caused by trypanosomes to their host. It is difficult to conclude which clinical signs are owing to a given parasite and only few studies have been made in this aspect to identify a specified sign to particular trypanosomes (Murray and Dexter, 1988; Garner et al., 2003).