Diagnostic value of two commercial chromatographic "patient-side" tests in the diagnosis of acute canine leptospirosis

作者:Gloor C I; Schweighauser A; Francey T; Rodriguez Campos S; Vidondo B; Bigler B; Schuller S*
来源:Journal of Small Animal Practice, 2017, 58(3): 154-161.
DOI:10.1111/jsap.12628

摘要

ObjectivesTo determine the diagnostic performance of two patient-side tests (RDT-1: Test-it and RDT-2 Witness (R) Lepto) in the early diagnosis of canine leptospirosis. MethodsRetrospective study of 108 dogs with leptospirosis and 53 controls. Leptospirosis was diagnosed based on compatible clinical and clinicopathologic signs and either a single microscopic agglutination test titre_ >800 (n=49), seroconversion (n=53), positive urine real time PCR (RT-PCR) (n=1), evidence of spirochaetes in silver-stained tissues (n=1) or a combination of these (n=4). Leptospirosis was excluded in dogs with a convincing alternative diagnosis and single microscopic agglutination testing titres _<200 (n=46) or lack of seroconversion (n=7). Indices of diagnostic accuracy of the rapid diagnostic tests were calculated by comparing admission rapid diagnostic test results to the final disease status. ResultsRapid diagnostic test-1 was performed in 118 dogs, rapid diagnostic test-2 in 69 dogs and both tests in 26 dogs. Weak positive results occurred frequently representing 226% (rapid diagnostic test-1) and 323% (rapid diagnostic test-2) of all positive tests in dogs with leptospirosis. If weak positive rapid diagnostic tests were considered positive, rapid diagnostic test-1 and rapid diagnostic test-2 had sensitivities of 82 and 76%, specificities of 91 and 100%, positive predictive values of 94% and 100% and negative predictive values of 73% and 74%, respectively. There were some technical problems with rapid diagnostic test-1. Clinical SignificanceThe diagnostic performance of the rapid diagnostic tests is similar to that reported for the microscopic agglutination test. Both can support a diagnosis of leptospirosis with high specificity but leptospirosis cannot be excluded based on a negative admission test result. Both RDTs are useful in conjunction with other confirmatory tests.

  • 出版日期2017