Urine culture in the evaluation of suspected neonatal sepsis

Clinical records of patients in a neonatal intensive care unit were reviewed to determine the efficacy of obtaining a urine culture in the detection of neonatal sepsis. During a 12-month period, 188 sets of concomitant blood and urine cultures were obtained in infants less than 72 hours of age (early onset group) and 189 sets of cultures in infants over 72 hours of age (late onset group). Blood cultures were positive in nine instances in the early onset group and 11 instances in the late onset group. All but one blood culture in each group was accompanied by a negative urine culture. Urine cultures alone were positive in two instances in the early onset group and 13 instances in the late onset group (P less than 0.05). Symptoms did not differentiate infants with bacteremia from infants with bacteruria. Culture of the urine was shown to be necessary for the detection of a significant number of late onset infections. Urine culture in the early onset age group had a significantly lower yield, and the risk of suprapubic bladder tap in this group may not be justified.