What’s New UTI
A trio of recent publications on pediatric UTI offer some insights. First, Mattoo et al offer a review of UTI diagnosis and management in children. Nadeem et al studied the optimal WBC cutoffs for diagnosing UTI, balancing overdiagnosis/overtreatment with underdiagnosis/missed UTIs, based on the specific gravity and found them to be: 3 WBC/hpf for spec grav < 1.011, 6 WBC/hpf for 1.011-1.020, and 8 WBC/hpf for spec grav > 1.020. And Liang et al reviewed 2144 PED visits in < 2yo and calculated likelihood ratios and posttest probabilities for various urinalysis findings. UTI prevalence was 9.2%, which the authors used as the pretest probability. Likelihood ratios for leukocytes were: 1+ 2.79. 2+ 7.53, 3+ 37.68. Nitrite positivity carried a LR of 25.35. WBC/hpf at 5-10 had a LR of 1.2 (95CI 0.7-2.04), 10-20 LR 1.82, 20-50 LR 11.18. Few bacteria had an LR of 1.46, moderate 6.05, many 14.04.