Modelling the control of tsetse and African trypanosomiasis through application of insecticides on cattle in Southeastern Uganda

[摘要] ENGLISH ABSTRACT: In Uganda, cattle are an important reservoir of Trypanosoma brucei rhodesiense, a parasitethat causes human African trypanosomiasis or sleeping sickness. We developed mathematicalmodels to examine the transmission of T. b. rhodesiense by tsetse vector species,Glossina fuscipes fuscipes in a host population that consists of humans, domestic and wildmammals, and reptiles. The models were developed and analysed based on the situation inTororo district in Southeastern Uganda, where sleeping sickness is endemic and which has acattle and human population of 40, 000 and 500, 000, respectively. Assuming populations ofcattle and humans only, the impact of mass chemoprophylaxis and vector control throughinsecticide-treated cattle (ITC) is evaluated. Keeping 12% or 82% of the cattle populationon insecticides that have an insecticidal killing effect of 100% at all times or trypanocidesthat have 100% efficacy, respectively, can lead to the control of T. b. rhodesiense in bothhumans and cattle. Optimal control of T. b. rhodesiense is shown to be achieved throughITC alone or a combination of chemoprophylaxis and ITC, the former being the cheapestcontrol strategy. Allowing for the waning effect of insecticides and including wildhosts,T. b. rhodesiense control can be achieved by keeping 21% or 27% of the cattle populationon insecticides through whole-body or restricted application, respectively. Restrictingthe treatment of insecticides to adult cattle only would require 24% or 33% of the adultcattle population to be kept on insecticides through whole-body or restricted application,respectively, to control T. b. rhodesiense. A cost-effectiveness and benefit-cost analysis ofusing ITC to control T. b. rhodesiense show that restricted application of insecticides isa cheaper and more beneficial strategy compared to whole-body treatment. The results ofthe study show that the restricted application of insecticides on cattle provides a cheap,safe and farmer-based strategy for controlling tsetse and trypanosomiasis.

[发布机构] Stellenbosch University