Urinary tract infection concordance with positive blood and cerebrospinal fluid cultures in the neonatal intensive care unit

Abstract

Urinary tract infections (UTI) are common in the neonatal intensive care unit (NICU). Blood, urine and cerebrospinal fluid (CSF) cultures are frequently obtained to evaluate for infection. We sought to determine the concordance between positive urine cultures and blood or CSF cultures. Infants <121 days of age with a UTI admitted to 322 NICUs managed by the Pediatrix Medical Group from 1997 to 2010 were identified. UTIs were defined by isolation of a single pathogenic organism in a urine sample obtained by catheterization or suprapubic tap. The UTI was concordant if the same organism was identified in the blood or CSF within 3 days of the urine culture. Of 5681 infants with a urine culture, 984 had 1162 UTIs. In total, 976 UTIs (84%) had a blood culture collected within 3 days, and 127 (13%) were concordant. Of the 1162 UTIs, 77 (7%) had a CSF culture collected within 3 days, and 2 (3%) were concordant. Collection of a urine culture in infants evaluated for late-onset sepsis is important. Concordance was observed in 13% of blood cultures and 3% of CSF cultures. These findings may be related to the initiation of empirical antimicrobial therapy before evaluation for disseminated infection or poor blood culture sensitivity.