Performance of an indigenous b-mercaptoethanolmodified antigen in comparison with a commercial reference in direct agglutination test for detection of canine visceral leishmaniasis

摘要

We compared the performance of a locally produced b-mercaptoethanol-modified promastigoteantigen (b-ME-Ag) of an indigenous Leishmania infantum strain against that of a trypsinizedLeishmania donovani reference (REF-Ag) in the direct agglutination test (DAT) for detection ofcanine visceral leishmaniasis (CVL). One hundred and fifty-one serum samples collected fromdogs belonging to four groups with different conditions were included. At a DAT titre of 1 : 320,statistically determined as optimal cut-off value for b-ME-Ag, and 1 : 160 for REF-Ag, a sensitivityand a specificity of 100% were estimated for b-ME-Ag in comparison with 96.6% and 100 %,respectively, for REF-Ag. Overall, levels of agglutination titres recorded for the two antigens werehighly concordant (Cohen’s k50.879) in both the CVL and non-CVL groups. Based on currentresults, and ease experienced in processing the antigen and reading the test outcome, werecommend incorporation of b-ME-Ag in DAT for confirmation or exclusion of suspected CVL indogs.