Enhancing Vector Refractoriness to Trypanosome Infection

The success of the Agency supported project to eradicate Glossina austeni from the island of Unguja, Zanzibar, using SIT has lead to considerable interest in utilizing this approach in other locations, and led to the African Union initiative on PATTEC (Pan African Tsetse and Trypanosomosis Eradication Campaign). Projects are underway in Ethiopia and Senegal with other projects in various African countries. To date, IAEA supported SIT projects have been in areas without human sleeping sickness, and disease transmission has inthe past been minimized by adding trypanocidal drugs to the blood meal when feeding sterile males before release. Nevertheless for future projects that could include areas of actual or potential human disease transmission it would be desirable to develop strains refractory to the transmission of trypanosomes as a much simpler and more effective method of ensuring that released sterile flies do not transmit any disease. Therefore it is essential to understand the mechanisms that limit the development of infections in tsetse and how these may be enhanced. CRP D42012 been studying the symbionts and pathogens of tsetse to understand their impact on the flies and therefore on colony management, sterile male performance and tsetse control. Recent research has indicated that some of these pathogens have an impact on the tsetse-trypanosomosis interaction, and may perhaps be manipulated to induce refractoriness to infection. This proposal is for a CRP to focus on a deeper and more focused understanding of the three way interaction between the vectors, their symbionts and trypanosomes, with the objective of determining if and how refractoriness may be induced.