Reverse transcriptase real time PCR for spliced leader RNA detection in blood and cerebrospinal fluid and neopterin detection will be carried out in the reference laboratory in Kinshasa, (index tests). The reference laboratory will be blinded to the results of the reference standard. For evaluation of diagnostic performance of the index tests, the reference standard will consist of classification of treatment outcome according to international standards applied for the clinical trial. Receiver operator curves, sensitivity and specificity of the different index tests for treatment outcome assessment will be determined at each follow-up time point. If sufficiently accurate, trypanosomal spliced leader RNA detection in blood would allow post-treatment follow-up without the need for lumbar punctures. Improved treatment outcome assessment will not only facilitate follow-up by avoiding the feared lumbar puncture but also speed up the development and implementation of new drugs. In addition, it will also improve management of patients in routine. The proposed research will impact on clinical decision and treatment outcomes, and contribute to successful HAT elimination.