CONTROL STRATEGIES FOR SLEEPING SICKNESS IN CENTRAL-AFRICA - A MODEL-BASED APPROACH

Vector control and the detection (followed by treatment) of infected i ndividuals are the two methods currently available for the control of sleeping sickness. The basic reproduction rate of a compartmental mode l is used to analyse and compare the two strategies. The efficiency of each strategy will depend on two epidemiologic parameters; the intrin sic contamination rate Q (closely related to the index of new contamin ations) that captures the potential spread of the disease, and the int rinsic removal rate from the first stage (intrinsic to the particular trypanosome strain and to the population's susceptibility). The model shows that when the intrinsic removal rate is low (that is, when there is a long first stage characteristic of an endemic situation) the det ection of sick individuals is more efficient than vector control. The situation is reversed when the removal rate is high (in an epidemic si tuation). The conclusions of the analysis are shown to be in general a greement with results obtained in two different sleeping sickness foci of Central Africa.