Evolutionary, regulatory and mediation aspects of T.b. rhodesiense and its endemicity in Lambwe Valley, Kenya.

The transmission of the human African trypanosomiasis (HAT) infection, also known as human sleeping sickness, depends on environmental factors operating at the mega-, macro-, and micro-scale levels. However, at the latter level T.b. rhodesiense parasite undergoes metacyclic development processes, controlled by its evolution, regulatory and mediation factors. Selective pressures acting on host-parasite interactions are thought to influence the genetics of the parasite and its hosts. In retrospect, the phenotypic difference responsible for the change in fitness of the parasite is complicated, since natural variation in a phenotype may be maintained by frequency-dependent selection, with species-specific fitness dynamics. Although little evidence exists on aspects of mutualism o f trypanosomes, it is possible that synergistic interactions among pathogens may be involved in the complex of phenotype variations. This paper considers the underlying dynamics with reference to the endemicity of the infection in Lambwe Valley ecosystem.