Serological Survey ofEhrlichia canisin Stray Dogs from Yucatan, Mexico, Using Two Different Diagnostic Tests

Abstract
Canine ehrlichiosis is a disease produced by the rickettsial organism Ehrlichia canis. Reported prevalence may vary greatly depending on the test and sampling method used. For the serological detection of antibodies against E. canis, the indirect immunofluorescence antibody test (IFA) is considered the gold standard. However, other available serological techniques such as the indirect immunoperoxidase technique (IPT) have not yet been tested and may be efficient in detecting specific antibodies. Prevalence found (8.7% and 8.1% for IFA and IPT, respectively) was lower than previously reported in the studied area despite the well-established technique used for the determination of antigens. A kappa value of 0.958 (95% CI 0.9–1.0) was found with a sensitivity and specificity for IPT of 92.59% (95% CI 80.8–99.9) and 99.9% (95% CI 99.8 –100), respectively. The positive predictive value was 99.9% and the negative predictive value was 99.29%. The IPT technique can be used safely for serological determination of E. canis antibodies.