La maladie de Chagas: évaluation des tests de dépistage au centre de transfusion sanguine des armées, prévalence dans les armées

Abstract

Chagas disease is a major public health problem in Latin and Central America, 15 to 20 million people are affected and some 100 million is at risk of acquiring Chagas disease. Chagas disease starts to appear in amazonian area and french Guyana. Three kits: Elisa Novagnost (Dade Behring), BioElisa Chagas (Orgentec) et Elisa Cruzi (BioMérieux) were compared using performance panel. Sensibility, reproductibility and specificity (using 40 serum of blood donors who never went to an endemic area) were evaluated. Orgentec assay (recombinant antigens) and BioMérieux assay (whole-epimastigote antigens) performed better than Dade Behring assay. The latter was discarded from the study at this stage. Lack of sensibility seems due to the antigenic composition. Reproductibility and specificity are good for the other two tests. Mixtures of recombinants antigens increased specificity, but sensibility is better using mixtures of whole-epimastigote antigens. For routine blood donor screening both tests must be performed. A prevalence study was done during 11 months on 1570 serum of military blood donors. Despite of a low prevalence (less than 0.7 per thousand), the entire donation from donors who were in the endemic area (7.95% from our whole population) are screened for antibody against Trypanosoma cruzi, with these two assays.