Validité, coût et faisabilité de la mAECT et CTC comme tests de confirmation dans la détection de la Trypanosomiase Humaine Africaine

Abstract

OBJECTIVES: To evaluate the validity, cost and feasibility of two parasitological tests for the confirmation of Human African Trypanosomiasis (HAT): the mini Anion-exchange Centrifugation Technique (mAECT) and Capillary Tube Centrifugation (CTC). METHODS: During a sleeping sickness screening campaign in 2004 we screened 6502 people in Kwamouth, DRC. Those with a positive result in the Card Agglutination Test for Trypanosomiasis (CATT) had a gland puncture, fresh blood examination, stained thick blood film, mAECT, CTC and CATT titration. Sensitivity and specificity of the confirmation tests were calculated using the combination of all parasitological tests as a reference standard. Each method was costed and its feasibility was assessed with structured interviews of the technicians. RESULTS: Sensitivity of classical parasitological methods was 44.8% (36.8-53.0), of CTC 56.5% (48.3-64.5) and of mAECT 75.3% (95% CI: 67.7-81.9). Cost per test was €2.82 for mAECT and €0.76 for CTC. Time per test was 29.78 min for mAECT and 18.25 min for CTC. These two tests were judged feasible in field conditions. CONCLUSION: CTC and mAECT used alone or in combination would bring a considerable improvement to q7HAT active case finding when used as confirmation tests in CATT-whole blood-positive persons. They proved feasible in operational conditions if a 220 V power supply can be guaranteed. As mAECT is more sensitive but also considerably more expensive, efficiency as well as feasibility considerations will have to guide the choice of the best algorithm. © 2006 Blackwell Publishing Ltd.