All febrile infants under 1 month old should receive a urine culture because of the prevalence of urinary tract infections and the inadequacy of other clinical parameters in identifying urinary tract infection risk, according to results of a recent study.
Approximately one in six infants aged 30 days or younger experienced urinary tract infections (UTIs), and males were more than twice as likely as females to have one, reported Dr. William Bonadio and Dr. Gary Maida of Maimonides Medical Center in New York.
Infants with a UTI should receive renal ultrasound imaging because nearly half of those with UTIs had radiographic anatomic abnormalities, the authors reported (Pediatr. Infect. Dis. J. 2014;33:342-4).
Of 670 febrile infants evaluated for sepsis in the emergency department at Maimonides Medical Center between 2004 and 2013, a total of 15.4% of the 651 receiving a urine culture had a UTI. Of these, 73% were male, and 47% had anatomic abnormalities appearing on renal ultrasound imaging.
The patients with abnormalities included 19 with pelviectasis and 26 with hydronephrosis. In the 21 patients with hydronephrosis who received a voiding cystourethrogram, 5 had vesicoureteral reflux. None of the infants had bacterial meningitis, and four had urosepsis.
Meanwhile the sensitivity of clinical symptoms, including fever height, CBC total white blood cell count, and urine dipstick test, was insufficient to determine risk of UTI in infants. Among those with UTIs, only 40% had a CBC total white blood cell count of at least 15,000/mm3, and 39% had a fever of 102° F or greater; 79% tested positive for leukocyte esterase or nitrite with a urine dipstick test.
"Reliance on urine dipstick test results to determine whether to perform a urine culture would have resulted in missed diagnosis of 21% of UTI cases in our cohort," the authors wrote. "Similarly, microscopic urinalysis was relatively insensitive at identifying those with underlying UTI."
Escherichia coli was the most common uropathogen, identified in 71% of the patients with UTI, followed by Enterococcus (10%), and Klebsiella species (10%).
The researchers did not report external funding. The authors reported no disclosures.