A Breakthrough in the Detection of Bacteria in Urine
American Journal of Veterinary Research
February 2016, Vol. 77, No. 2, Pages 162-166
Diagnostic accuracy of a rapid immunoassay for point-of-care detection of urinary tract infection in dogs
Megan E. Jacob, PhD; M. Denise Crowell, MS; Megan B. Fauls, BS; Emily H. Griffith, PhD; Kelli K. Ferris, DVM
OBJECTIVE: To determine the diagnostic accuracy of a rapid immunoassay (RIA) for point-of-care detection of urinary tract infection (UTI) of dogs, compared with criterion-referenced diagnosis with bacterial culture.
SAMPLE: 200 urine samples obtained from dogs and submitted to a veterinary microbiology diagnostic laboratory for routine bacterial culture and antimicrobial susceptibility determination.
PROCEDURES: Samples were evaluated by use of quantitative bacterial culture and the
RIA. Sensitivity, specificity, and positive and negative predictive values of the RIA were
calculated; results of bacterial culture were the criterion-referenced outcome. A ? statistic
was calculated to determine agreement between bacterial culture and RIA results.
RESULTS: 56 of 200 (28%) urine samples had positive results for bacterial growth by
use of culture methods; there were 38 (19%) positive results likely to be associated
with bacterial UTI on the basis of sample collection method and bacterial concentration.
Sensitivity and specificity of the RIA f or detecting samples likely to be associated
with UTI (? 1,000 C FUs/mL) were 97.4% and 98.8%, respectively. The positive and negative
predictive values of the RIA f or bacterial cultures with likely UTI w ere 0.949 and 0.994,
respectively. Agreement between bacterial culture and RIA outcome for UTI was substantial
(weighted ? , 0.718).
CONCLUSIONS AND CLINICAL RELEVANCE: The RIA test evaluated in this study accurately detected UTI of dogs, compared with detection with the criterion-referenced bacterial culture method. Use of this point-of-care RIA could allow clinicians to
diagnose UTI at the time of a patient visit and provide information useful for immediately
initiating empirical antimicrobial treatment. (Am J Vet Res 2016;77:162Â166)
Department of Population Health and Pathobiology, North Carolina State University, Raleigh, NC 27607. ( Jacob); North Carolina State Veterinary Hospital, North Carolina State University, Raleigh, NC 27607. (Crowell, Fauls); Department of Statistics, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, NC 27607. (Griffith);
Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607. (Ferris)
Address correspondence to Dr. Jacob (firstname.lastname@example.org).