Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + I. DEFINITION Download Section PDF Listen +++ ++ Urinary tract infection (UTI) is the presence of pathogenic bacteria or fungus in the urinary tract. + II. INCIDENCE Download Section PDF Listen +++ ++ Various series report an incidence of 0.5–1.0% in term infants weighing >2500 g and higher rates (3–5%) in premature infants or infants weighing <2500 g. Escherichia coli remains the most common pathogen, followed by other gram-negative rods. + III. PATHOPHYSIOLOGY Download Section PDF Listen +++ ++ Inoculation of the normally sterile urinary tract is thought to occur via fecal-perineal contamination, instrumentation, or spread from an infectious process outside of the urinary tract. + IV. RISK FACTORS Download Section PDF Listen +++ ++ Any altered anatomy (ie, posterior urethral valves, vesicoureteral reflux, ureteropelvic junction obstruction) or derangement in normal bladder function predispose to UTI. For hospital-acquired infections, indwelling Foley catheters or recent instrumentation are the most common risk factors. In addition, uncircumcised males and patients with systemic infectious processes or immunosuppression are at greater risk. + V. CLINICAL PRESENTATION Download Section PDF Listen +++ ++ Infants may appear acutely toxic (respiratory distress, apnea, bradycardia, hypoglycemia, poor perfusion) or present with nonspecific findings of lethargy, irritability, poor feeding, vomiting, jaundice, or failure to thrive. + VI. DIAGNOSIS Download Section PDF Listen +++ ++ Laboratory studies Urine culture. Suprapubic aspiration or bladder catheterizations are the only 2 methods of obtaining a reliable urine culture in a neonate (see Chapters 25 and 26). Cultures obtained from a suprapubic bladder aspiration or urethral catheterization that grow >50,000 colony-forming units of a single organism and have evidence of pyuria on urinalysis are interpreted as positive. Clean-catch or collection bag specimens often are inaccurate due to contamination and are only clinically reliable if the culture demonstrates no growth. Urine culture is no longer recommended in infants <72 hours of age in an early-onset sepsis workup and is more appropriately done for late-onset sepsis workup. Urinalysis. Leukocyte esterase is the most sensitive (83%) finding on a urinalysis and has a specificity of 78%. The presence of nitrites is 98% specific but is only has a sensitivity of 53%. Detection of bacteria by microscopy has high interexaminer variability, but is as high as 81% sensitive and 83% specific in some hands. No single finding is diagnostic; however, when there is microscopic bacteriuria or pyuria in addition to the presence of leukocyte esterase or nitrites, a urinalysis is >99% sensitive and 70% specific. + VII. MANAGEMENT Download Section PDF Listen +++ ++ Initial antibiotic treatment. For the majority of neonatal cases, initial treatment with broad-spectrum intravenous (IV) antibiotics is appropriate (usually Ampicillin and Gentamicin). In nontoxic infants over a month of age, oral therapy has been found to be as efficacious as IV therapy. (For dosages and other pharmacologic information, see Chapter 148.) Further investigations. All neonates with a febrile UTI or suspected anatomic abnormality require renal/bladder ultrasonography, and voiding cystourethrogram (VCUG). The American Academy of Pediatrics guidelines no longer recommend VCUG at the time of a first febrile urinary tract infection in infants >2 months of age. Until a national prospective randomized trial (RIVUR [Randomized Intervention for Children With Vesicoureteral Reflux]; estimated completion late 2013) clarifies the effectiveness or lack thereof of prophylactic antibiotics in infants, we feel that a VCUG at the time of the first febrile UTI during infancy is still warranted to evaluate urinary tract anatomy and VUR. Within the next few years, data from the RIVUR study will be available, providing further insight into the role of prophylactic antibiotics and thus VCUG in children with UTI. + SELECTED REFERENCES Download Section PDF Listen +++ + +Hoberman A, Wald ER, Hickey RW et al.. Oral versus initial intravenous therapy for urinary tract infections in young febrile children. Pediatrics. 1999;104:79–86.CrossRef [PubMed: 10390264] + +Hoberman A, Wald ER, Reynolds EA, Penchansky L, Charron M. Pyuria and bacteriuria in urine specimens obtained by catheter from young children with fever. Pediatrics. 1994;124:513–519.CrossRef+ +Ma JF, Shortliffe LM. Urinary tract infection in children: etiology and epidemiology. Urol Clin North Am. 2004;31:517–526.CrossRef [PubMed: 15313061] + +Subcommittee on Urinary tract infection, Steering Committee on Quality Improvement and Management. Urinary tract infection. Clinical practice guideline for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months. Pediatrics. 2011;128;595.CrossRef [PubMed: 21873693] + +To T, Agha M, Dick PT, Feldman W. Cohort study on circumcision of newborn boys and subsequent risk of urinary-tract infection. Lancet. 1998;352:1813–1816.CrossRef [PubMed: 9851381]