1. Thursday, February 11, 2010 Hussein Unwala PEM Fellow

2.  Urinary tract infections account for 0.7% of all pediatric office encounters and 5%-14% of pediatric emergency department visits in the US.  If not detected and treated promptly, a UTI can lead to renal scarring, hypertension, and end-stage renal disease Freedman AL, Urologic Diseases in America Project. Urologic diseases in North America Project: trends in resource utilization for urinary tract infections in children. J Urol. 2005;173(3):949-954

3. Copyright restrictions may apply. Shaikh, N. et al. JAMA 2007;298:2895-2904. Pooled Prevalence of UTI in Infants by Age and Sex

4.  Bacteriuria: ◦ Recovery of any organisms from a suprapubic specimen, at least 5 x 107 CFUs/L from a catheterized specimen, or at least 1 x 108 CFUs/L from a clean-catch specimen. +  Pyuria: ◦ The presence of at least 10 WBC/microliter from an unspun specimen examined using a counting chamber.  Common uropathogens include E. coli (accounting for approximately 85% of UTIs in children) Klebsiella, Proteus, Enterobacter, Citrobacter, Sta phylococcus saprophyticus, and Enterococcus.

6. Copyright restrictions may apply. Shaikh, N. et al. JAMA 2007;298:2895-2904. Diagnostic Accuracy of UTI Symptoms Among Infants Aged 0 to 24 Months

8. Copyright restrictions may apply. Shaikh, N. et al. JAMA 2007;298:2895-2904. Diagnostic Accuracy of Urinary Tract Infection Signs Among Infants Aged 0 to 24 Months

9. Copyright restrictions may apply. Shaikh, N. et al. JAMA 2007;298:2895-2904. Likelihood Ratios for Combination of Signs and Symptoms in Infants Aged 0 to 24 Monthsa

10. Copyright restrictions may apply. Shaikh, N. et al. JAMA 2007;298:2895-2904. Diagnostic Accuracy of Urinary Tract Infection Symptoms Among Verbal Children

11.  If an infant is ill enough to begin empiric antibiotic treatment, urine culture should be obtained by suprapubic aspiration or by catheterization. ◦ The false-positive rate of urine cultures obtained by bag collection was found to be too high to be clinically acceptable. ◦ suprapubic aspiration of urine for culture is considered the ‘gold standard’.  Practice parameter: the diagnosis, treatment, and evaluation of the initial urinary tract infection in febrile infants and young children. American Academy of Pediatrics. Committee on Quality Improvement. Subcommittee on Urinary Tract Infection. Pediatrics 1999; 103:843–852.

12.  Good agreement with “clean catch” urine cultures vs. urine catheterization in uncircumsized males < 2 years, but not in females < 2  Lau AY et al, A comparative study on bacterial cultures of urine samples obtained by clean-void technique versus urethral catheterization. Acta Paediatr 2007; 96:432–436

13.  Delays of more than two hours between collection and examination often causes unreliable results  Rabinovitch A. Urinalysis and collection, transportation, and preservation of urine specimens: approved guideline. 2d ed. Wayne, Pa.: National Committee for Clinical Laboratory Standards, 2001. NCCLS document GP16-A2.

15. Summary of results for studies of dipstick tests Dipstick positive for: Number of studies Range in LR+ Pooled LR+ (95 % CI)* Range in LR- Pooled LR- (95 % CI)* Nitrite232.5 – 439.615.9 (10.7, 23.7)0.12 – 0.86 0.51 (0.43, 0.60) LE142.6 – 32.25.5 (4.1, 7.3)0.02 – 0.66 0.26 (0.18, 0.36) Nitrite or LE153.0 – 32.26.1 (4.3, 8.6)0.03 – 0.39 0.20 (0.16, 0.26) Nitrite and LE96.3 – 197.128.2 (17.3–46.0)0.07 – 0.86 0.37 (0.26, 0.52) Glucose425.2 – 156.166.3 (20.0, 219.6)0.02 – 0.38 0.07 (0.01, 0.83) Protein21.7 & 1.8na0.78 & 0.96na Blood12.3na0.84na LE and protein117.4na0.12na Nitrite, blood, or protein12.7na0.28na Nitrite, blood, or LE11.3na0.50na Nitite, blood and LE13.5na0.19na Nitrite, LE and protein23.1 & 69.2na0.05 & 0.17na Nitrite, LE, or protein11.9na0.05na Nitrite, LE, protein, or blood18.0na0.19na * There was significant heterogeneity in all pooled estimates therefore these should be interpreted with caution Whiting et al. BMC Pediatrics 2005 5:4 doi:10.1186/1471-2431-5-4

17.  A dipstick test positive for both nitrite and LE has the highest positive likelihood ratio (28.2, 95% CI: 17.3, 46.0) suggesting that this test combination may be used to rule in disease.  A dipstick test negative for both LE and nitrite has the best negative likelihood ratio (0.20, 95% CI: 0.16, 0.26) suggesting that this test combination may be used to rule out disease Whiting P et. al, Rapid tests and urine sampling techniques for the diagnosis of urinary tract infection (UTI) in children under five years: a systematic review. J.BMC Pediatr. 2005 Apr 5;5(1):4.

18. Summary of results for studies of microscopy Microscop y positive for: Number of studies Range in LR+ Pooled LR+ (95 % CI)* Range in LR- Pooled LR- (95 % CI)* Pyuria281.3 – 27.7 5.9 (4.1, 8.5) 0.04 – 0.68 0.27 (0.20, 0.37) Bacteriuria221.6 – 304.8 14.7 (8.6, 24.9) 0.01 – 0.48 0.19 (0.14, 0.24) Pyuria or bacteriuria 81.5 – 5.9 4.2 (2.3, 7.6) 0.02 – 0.27 0.11 (0.05, 0.23) Pyuria and bacteriuria 82.7 – 281.0 37.0 (11.0, 125.9) 0.07 – 0.56 0.21 (0.13, 0.36) * There was significant heterogeneity in all pooled estimates therefore these should be interpreted with caution Whiting et al. BMC Pediatrics 2005 5:4 doi:10.1186/1471-2431-5-4

19. Whiting P et. al,J.BMC Pediatr. 2005 Apr 5;5(1):4.

20.  The test with the best combination of sensitivity and specificity was Gram stain (positive LR: 18.5; negative LR: 0.07).  Urine dipstick tests performed nearly as well; the presence of both LE and nitrites had a positive LR of 12.6, whereas the absence of both LE and nitrite had a negative LR of 0.13  Gorelick and Shaw, Screening Tests for Urinary Tract Infection in Children: A Meta-analysis, Pediatrics 1999;104;e54

21. Shaikh, N. et al. JAMA 2007;298:2895-2904. Diagnostic Algorithm for Febrile Male Infants Aged 3 to 24 Months Suspected of Having a UTI

22. Copyright restrictions may apply. Shaikh, N. et al. JAMA 2007;298:2895-2904. Diagnostic Algorithm for Febrile Female Infants Aged 3 to 24 Months Suspected of Having a UTI

23. Copyright restrictions may apply. Shaikh, N. et al. JAMA 2007;298:2895-2904. Diagnostic Algorithm for Verbal Children Older Than 24 Months With Urinary or Abdominal Symptoms

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