Urinary tract infection in outpatient febrile infants younger than 30 days of age: a 10-year evaluation.

BACKGROUND: To determine the prevalence of outpatient-diagnosed urinary tract infection (UTI) in consecutive febrile neonates ≤ 30 days of age and correlate demographic, laboratory and radiographic imaging results with infectious etiology.

METHODS: Review of medical records of consecutive febrile infants ≤ 30 days of age presenting to an urban pediatric emergency department during a 10-year period, whose policy is to perform a sepsis evaluation (urine culture obtained by bladder catheterization) and hospitalize for parenteral antibiotic therapy pending culture results.

RESULTS: Of 670 febrile neonates ≤ 30 days of age evaluated for sepsis, urine culture was obtained in 651 cases (97%). Of 100 patients with UTI (15.4%), 73% were male; the most common uropathogens were Escherichia coli (71%), Enterococcus (10%) and Klebsiella sp. (10%). In all, 39% had a maximum documented fever ≥ 102 °F, and 40% had CBC total white blood cells count ≥ 15,000/mm(3). Urine dipstick test was positive for leukocyte esterase or nitrite in 79%. Renal ultrasound performed in 95 patients (95%) showed anatomic abnormalities in 47%; 5/26 (24%) with hydronephrosis had vesicoureteral reflux on voiding cystourethrogram. Four patients had urosepsis; none had bacterial meningitis and no patients died.

CONCLUSIONS: UTI affects approximately 1 in 6 febrile neonates ≤ 30 days of age. Males are affected 2.5-times greater than females. E. coli continues to be the predominant uropathogen. Clinical parameters like height of fever, CBC total white blood cell count and urine dipstick test lack sensitivity in identifying UTI risk in the outpatient setting. Only 4 infants had urosepsis (4%). Nearly half of neonates with UTI have a radiographically identified anatomic abnormality. All febrile young infants should receive performance of a urine culture; those with UTI require imaging.