In the last decade, the prevalence of Trypanosoma brucei gambiense (Tbg) human African trypanosomiasis (HAT) has dramatically decreased and HAT has been targeted for elimination by 2020. Integration of HAT diagnosis and treatment in peripheral health centres and sustainable monitoring of eliminated foci are vital for Tbg HAT elimination. Development of safe and efficacious drugs applicable in an elimination context would be accelerated by the availability of an early test-of-cure. In line with the EDCTP2 scope and call objectives, the DiTECT-HAT seeks to validate the performance of diagnostic tools and algorithms for early and rapid diagnosis of Tbg HAT, for passive case detection, for post-elimination monitoring and for assessing the therapeutic response.
Firstly, for passive case detection (WP2), we will determine the diagnostic performance and cost-efficiency of RDTs performed in peripheral health centres, and of diagnostic algorithms combining RDTs with serological and/or molecular tests on filter paper performed at regional reference centres. Diagnostic algorithms with high positive predictive values will improve cost-effectiveness of passive case detection and might, in the near future, allow scenarios of testing and treating without the need for parasitological confirmation.
Secondly, for post-elimination monitoring (WP3), we propose to determine the feasibility and cost-efficiency of different diagnostic algorithms with serological and molecular high-throughput tests. General health workers performing house to house visits in eliminated HAT foci can easily collect blood on filter paper and send it to regional HAT reference centers for analysis. This study should allow for defining thresholds for a “transmission alarm” that should trigger reactive case finding to avoid re-emergence of HAT.
Finally, the accuracy of neopterin and trypanosomal spliced leader RNA detection as early test-of-cure (WP4) will be determined in therapeutic trials. Early treatment outcome assessment will not only speed up the development and implementation of new drugs for HAT, but will also improve management of relapsing patients in routine patient care.