Evaluation of a Catalase‐Based Urine Test for the Detection of Urinary Tract Infection in Dogs and Cats

Abstract

Background Bacterial infection of the urinary tract is a common disorder in dogs and cats. Although microscopic examination of urine sediment is routinely used to screen for infection, this test can lack sensitivity or require expertise. A reliable in‐clinic screening test would be a useful adjunct for the identification of dogs and cats with bacterial urinary tract infection (UTI). Hypothesis That a catalase‐based urine test (Accutest Uriscreen™) is a more sensitive screening test for UTI in dogs and cats than urine microscopic sediment examination. Animals One hundred and sixty client‐owned dogs and cats. Methods Surplus urine from animals presented to a veterinary teaching hospital was used in this prospective observational study. A routine urinalysis, aerobic bacterial culture, and the Uriscreen test were performed on cystocentesis samples. Sensitivity and specificity with 95% confidence intervals and positive and negative likelihood ratios were calculated for Uriscreen and microscopic sediment examination using culture results as the gold standard. Results Bacterial culture was positive in 27/165 (16.4%) samples. The sensitivity, specificity, and positive and negative likelihood ratios for the Uriscreen were 89%, 71%, 3.0, and 0.15, respectively. Sensitivity, specificity, and positive and negative likelihood ratios for urine sediment microscopic examination were 78%, 90%, 7.8, and 0.24, respectively. Conclusions and Clinical Importance The Uriscreen is a more sensitive screening test for UTI in dogs and cats than sediment examination; however, the urine sediment examination was more specific. A negative Uriscreen result helps exclude UTI; however, urine bacterial culture is still necessary to exclude or confirm UTI in all cases.

Diagnostic accuracy of a point‐of‐care test using voided urine samples for detection of bacteriuria in dogs with signs of lower urinary tract disease

“…The RIA had higher specificity and rapid results and used voided urine. 5,6,7 The high NPV should decrease the recommendation for aerobic urine culture and susceptibility testing, thus saving the client money, but also should prevent unnecessary treatment with antibiotics. A negative RIA result also allows the veterinarian to quickly focus diagnostic testing on causes of lower urinary tract clinical signs other than bacterial UTI.…”

“…To achieve these results required that all slides be reviewed by a single board‐certified clinical pathologist and urine be collected by cystocentesis. Other tests include compartmented bacteriologic, urine dipstick paddle, and rapid urine catalase tests 5,6,7 . The former 2 tests required a minimum of 24 hours to complete, and all 3 were performed on urine collected by cystocentesis or urinary catheterization to achieve good performance.…”

Comparison of a Chromogenic Urine Culture Plate System (UTid+) and Conventional Urine Culture for Canine and Feline Specimens

“…Olin et al evaluated a culture-based POC test which had similar overall accuracy (94%), but lower sensitivity (81.0%) and higher specificity (99%) than UTid+ [ 13 ]. UTid+, in terms of sensitivity and specificity, performed considerably better than results published for a catalase-based urine test (89.0% and 71.0% respectively), but worse than results for a rapid immunoassay (RIA-97.4% and 98.8% respectively) [ 10 , 14 ]. Neither of these can identify bacteria to a genus level like UTid+, but the RIA can distinguish between Gram-negative and Gram-positive bacteria [ 10 ].…”

“…In a study of a different POC urine test, one of three Proteus spp.-positive cultures showed the same type of discordant result as the UTid+ system (positive on conventional culture and negative on POC test) but the non-culture-based assays detected Proteus spp. completely [ 10 , 13 , 14 ].…”

“…Sediment analysis, as part of urinalysis, may be used to identify bacteriuria at POC but interpretation likely depends on the skill of the evaluator and has been shown to have low sensitivity [ 9 ]. Other POC tests such as a rapid immunoassay, a urine catalase test, a urine dipstick paddle culture system, and compartmented bacterial culture plates have been evaluated for use in companion animal veterinary medicine and demonstrate variable accuracy [ 10 , 11 , 12 , 13 , 14 ].…”