A comparative study of nested-PCR and direct agglutination test (DAT) for the detection of Leishmania infantum infection in symptomatic and asymptomatic domestic dogs.

Venous blood samples were collected from dogs without clinical signs (n  =  30) and with clinical signs (n  =  35) suggestive of Leishmania infantum infection. Among 65 samples examined, Leishmania DNA was detected by nested-PCR in 89.23% (58/65). Furthermore, 86.15% (56/65) nested-PCR positive samples were also DAT positive. The results of the DAT sensitivity test were 96.43% and 96.67% in symptomatic and asymptomatic dogs, respectively, while the specificity was 100.00% and 60.00% in symptomatic and asymptomatic dogs, respectively. The results of this study also pointed out substantial concordance between DAT test and nested-PCR method in both symptomatic dogs (Κ  =  0.783; P  <  0.001) and asymptomatic dogs (Κ  =  0.618; P  <  0.001). Thus, DAT represents as a simple and economic tool for initial diagnosis of CVL particularly in endemic areas of the disease.