Prospects for control of African trypanosomiasis by tsetse vector manipulation

The extensive antigenic variation phenomena African trypanosomes display in their mammalian host have hampered efforts to develop effective vaccines a gainst trypanosomiasis. Human disease management aims largely to treat infe cted hosts by chemotherapy, whereas control of animal diseases relies on re ducing tsetse populations as well as on drug therapy. The control strategie s for animal diseases are carried out and financed by livestock owners, who have an obvious economic incentive. Sustaining largely insecticide-based c ontrol at a local level and relying on drugs for treatment of infected host s for a disease for which there is no evidence of acquired immunity could p rove extremely costly in the long run. It is more likely that a combination of several methods in an integrated, phased and area-wide approach would b e more effective in controlling these diseases and subsequently improving a gricultural output. New approaches that are environmentally acceptable, eff icacious and affordable are clearly desirable for control of various medica lly and agriculturally important insects including tsetse. Here, Serap Akso y and colleagues discuss molecular genetic approaches to modulate tsetse ve ctor competence.