Validation of a serological test for the diagnosis of canine rickettsial disease

Canine vector borne diseases include a variety of illnesses affecting domestic dogs worldwide. Clinical abnormalities are often nonspecific during rickettsial infections, and coinfections caused by other tick-transmitted agents may be common. The aim of this study was to validate a differential serological assay for the diagnosis of rickettsial infections by the indirect fluorescent antibody (IFA) test. Sensitivity (DSe), specificity (Dsp), accuracy (Acc), positive and negative predictive values (PPV and NPV), positive and negative likelihood ratios (LR+ and LR-), Cohen's Kappa agreement, Youden's J index and odds values were calculated in order to define the positive and negative post-test probability and to establish a link between clinical signs compatible with a rickettsial infections and serological confirmation.