Control of the African trypanosomiases with special reference to land use.

There is a need to reassess the role of the trypanosomiases, both human and animal, in African ecology and economy. Withdrawal of control services from the Congo basin was followed by a resurgence of infection from ancient foci, many of them thought to have been extinguished. Successful elimination of Glossina in savanna habitats has sometimes been followed by reinvasion causing massive epizootics. Elsewhere continued recession of the tsetse fly has been followed by cattle population growth which is periodically interrupted by catastrophic pasture famines.Efficiency of control rather than large-scale eradication should be the immediate aim. Efficient control keeps trypanosomiasis at a tolerable level in relation to the competence of medical and veterinary services and ensures that the beneficial effects of disease in maintaining a balance between natural resource potential of the continent and the energy output of its inhabitants, are retained until they can be replaced by new social and economic controls integrated in local cultures.Many ideas about control planning formulated before 1960 are now irrelevant. To provide foundations for a new policy 3 requirements must be fulfilled. The first is to understand the nature of natural foci of infection of trypanosomiasis; the second is to collate knowledge of land-use potentials of the fly-belts; the third is to find a means of integrating information to achieve balanced control programmes. To do this a formal mathematical study of the epidemiology and epizootiology of the trypanosomiases should be initiated.