Relationship between the estimated annual gambiense-HAT incidence and the positivity of serological tests. The annual incidence is expressed as the mean number of reported HAT cases per 10,000 inhabitants calculated over the 2010–2014 period. CATT = Card Agglutination Test for Trypanosomiasis; CATTB = CATT on blood; CATTP = CATT on plasma; TL = Immune Trypanolysis LiTat 1.3; + = positive test; − = negative test. Correlation between variables were assesed by the Spearman’s rank test.