Performance of a Recombinant LipL32 Based Rapid In-clinic ELISA (SNAP® Lepto) for the Detection of Antibodies Against Leptospira in Dogs

The purpose of this study was to compare the performance of SNAP (R) Lepto, a LipL32-based rapid enzyme-linked immunosorbent assay (ELISA) to the serological gold standard microscopic agglutination test (MAT) for the detection of antibodies to Leptospira spp in a broad population of canine samples. Four hundred and sixty serum samples submitted for MAT testing at IDEXX Reference Laboratories were tested on SNAP Lepto. Positive percent agreement between the two tests was 83.2% for samples with peak MAT titers >= 1: 800, 64.9% for samples with peak MAT titers ranging from 1: 100 to 1: 400, and 79.2% for samples with peak MAT titers >= 1: 100. Negative percent agreement between these tests was 82.1% in this population. One hundred and fifty MAT negative serum samples from healthy dogs in Alaska were tested by SNAP Lepto, and the percent agreement was 96.0%. Fifty-two serum samples positive for anti-Borrelia burgdorferi antibodies were tested. All 52 samples were negative by MAT, and 51/52 samples were negative on SNAP Lepto. Serial serum samples from 28 dogs following Leptospira vaccination were tested by MAT and SNAP Lepto. MAT results were positive in 27/28 dogs at week 3 (highest peak titer of 1: 3200), 28/28 dogs at week 4 (highest peak titer of 1: 6400), 3/21 dogs at week 52 (highest peak titer of 1: 200), and 15/19 dogs at week 56 (highest peak titer of 1: 1600). In comparison, positive SNAP Lepto test results were observed in 15/28 dogs at week 3, 22/28 dogs at week 4, 5/21 dogs at week 52, and 16/19 dogs at week 56. In this study, SNAP Lepto demonstrated similar performance to the MAT for the detection of antibodies to Leptospira spp.