Medical diagnosis procedure during IVR. Clinical and environmental suspected cases are first screened by CATT. If positive, the lymph nodes of individuals are examined. CATT-positive individuals who are negative for LN and TL are considered HAT-negative. All TL-positive subjects must be checked during the active screening. CATT+ = Card Agglutination Test for Trypanosomiasis positive; CATT− = Card Agglutination Test for Trypanosomiasis negative; LN+ = Lymph Node examination positive; LN− = Lymph Node examination negative; TL+ = Trypanolysis positive; TL− = Trypanolysis negative; NCPHAT: National Control Programme of HAT. TL is performed afterwards in the laboratory with the collected filter paper.