SAN FRANCISCO – Serum leukocytosis, pyuria, and urine leukocyte esterase have been identified as predictors of urinary tract infection (UTI) in infants younger than 90 days of age, with males being more likely to develop UTI than females.
The chance of the infection declined in older infants.
“Really young infants have a less well developed immune system, which may increase their susceptibility to UTIs,” said Sarah Berman, DO, a pediatric resident at Winthrop-University Hospital, Mineola, N.Y.
Brian Hoyle/Frontline Medical News
Dr. Sarah Berman
In 2011, the American Academy of Pediatrics issued “Urinary Tract Infection: Clinical Practice Guidelines for the Diagnosis and Management of the Initial UTI in Febrile Infants and Children 2 to 24 Months” (Pediatrics. 2011. doi: 10.1542/peds.2011-1330) concerning the diagnosis and management of the presence of bacteria in urine – a possible warning sign of UTI, but the AAP guidelines did not consider infants in the first 2 months of life.
To address this gap, the Winthrop-University Hospital researchers reviewed the medical records for all infants younger than 90 days of age diagnosed with UTI, fever, or viral illness from the beginning of 2009 to September 2015. Residence in neonatal intensive care, known congenital abnormalities, and prior antibiotic use were grounds for exclusion. Standard growth-based definitions of UTI and bacteriuria were used.
Of the 315 mainly white or Hispanic patients, 73 had a diagnosis of UTI and 261 did not. Both groups had the same mean age of 45 days. Fever within 24 hours of admission was more prevalent in those without UTI than those with (57% vs. 41%; P = .035). Those with UTI were significantly more likely (all P lesser than .001) to display serum leukocytosis (35% vs. 12%), pyuria (71% vs. 12%), and urine detection of leukocyte esterase (87% vs. 14%) and nitrite (19% vs. 0%).
In a univariate analysis, factors that were associated with UTI included serum leukocytosis, white blood cells in the urine, and urine leukocyte esterase, with fever within 24 hours of admission associated with reduced chance of UTI. A multivariate analysis that accounted for age, gender, and gestational age identified serum leukocytosis, pyruria, urine leukocyte esterase, and male sex as predictors of UTI, with increased odds ratio of 6.25, 3.19, 28, and 3.88, respectively.
The reduced likelihood of UTI in those who developed a fever within 24 hours of admission held up in the multivariate analysis (odds ratio 0.34).
Validation of the findings will require a prospective study, which is in the planning stage. If the findings bear out, the result could be improved diagnosis of UTI from birth onward, according to Dr. Berman.
Dr. Berman reported having no relevant financial disclosures.