Early Antibiotic Treatment for Pediatric Febrile Urinary Tract Infection and Renal Scarring

Abstract

IMPORTANCE Existing data regarding the association between delayed initiation of antimicrobial therapy and the development of renal scarring are inconsistent. OBJECTIVE To determine whether delay in the initiation of antimicrobial therapy for febrile urinary tract infections (UTIs) is associated with the occurrence and severity of renal scarring. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study that combined data from 2 previously conducted longitudinal studies (the Randomized Intervention for Children With Vesicoureteral Reflux trial and the Careful Urinary Tract Infection Evaluation Study). Children younger than 6 years with a first or second UTI were followed up for 2 years. EXPOSURE Duration of the child's fever prior to initiation of antimicrobial therapy for the index UTI. MAIN OUTCOMES AND MEASURES New renal scarring defined as the presence of photopenia plus contour change on a late dimercaptosuccinic acid renal scan (obtained at study exit) that was not present on the baseline scan. RESULTS Of the 482 children included in the analysis, 434 were female (90%), 375 were white (78%), and 375 had vesicoureteral reflux (78%). The median age was 11 months. A total of 35 children (7.2%) developed new renal scarring. Delay in the initiation of antimicrobial therapy was associated with renal scarring; the median (25th, 75th percentiles) duration of fever prior to initiation of antibiotic therapy in those with and without renal scarring was 72 (30, 120) and 48 (24, 72) hours, respectively (P = .003). Older age (OR, 1.03; 95% CI, 1.01-1.05), Hispanic ethnicity (OR, 5.24; 95% CI, 2.15-12.77), recurrent urinary tract infections (OR, 0.97; 95% CI, 0.27-3.45), and bladder and bowel dysfunction (OR, 6.44; 95% CI, 2.89-14.38) were also associated with new renal scarring. Delay in the initiation of antimicrobial therapy remained significantly associated with renal scarring even after adjusting for these variables. CONCLUSIONS AND RELEVANCE Delay in treatment of febrile UTIs and permanent renal scarring are associated. In febrile children, clinicians should not delay testing for UTI.

Reaffirmation of AAP Clinical Practice Guideline: The Diagnosis and Management of the Initial Urinary Tract Infection in Febrile Infants and Young Children 2–24 Months of Age

“…The study also noted that the rate of scarring increased minimally between days 1 and 2 and between days 2 and 3 but was much higher thereafter. 17 …”

Association Between Uropathogen and Pyuria

“…A delay in treatment has been associated with a higher likelihood of renal scarring. [8][9][10][11] This may partly explain why, in a recent meta-analysis, children with UTIs caused by non-E coli organisms were more likely to develop renal scarring. 12 Our results suggest that pyuria may not always be present in children with UTIs, especially those caused by Enterococcus species, Klebsiella species, or P aeruginosa.…”

Uropathogens and Pyuria in Children With Neurogenic Bladders

“…4 The results of routine urinalyses are frequently used to determine if empirical antibiotics are warranted before the availability of urine culture results. Although timely initiation of antibiotics can prevent the progression of infection and decrease the risk of renal scars, 5 unnecessary antimicrobial agents contribute to the emergence of bacterial resistance. In the absence of more accurate biomarkers of infection to help antibiotic selection, understanding the limitations of the routine urinalysis in predicting specific uropathogens is necessary.…”