Increasing incidence of gram-negative rod bacteremia in a newborn intensive care unit

To determine whether there has been an increase in the incidence or a change in the epidemiology of gram-negative rod (GNR) bacteremia in patients in a newborn special care unit.

Retrospective review of GNR bacteremia in patients hospitalized in the NBSCU at Yale-New Haven Hospital during a 10-year period.

There were 120 isolates from 113 episodes of GNR bacteremia during the study period. The incidence of GNR bacteremia increased from a mean of 10.2 to 25.5 (P = 0.017) episodes of GNR bacteremia per 1000 admissions per year between the time periods 1988 to 1994 and 1995 to 1997, respectively, paralleling an increase in the overall incidence of bacteremia. The increase in GNR bacteremia in these two groups was not related to changes in the patient population, the number of admissions or duration of hospitalization. Stepwise multivariate analysis identified two independent variables associated with infants who had GNR bacteremia during the period 1995 to 1997 as compared with 1988 to 1994, maternal intrapartum antibiotics (odds ratio, 4.9; 95% confidence interval, 1.9 to 12.6) and the presence of a percutaneous central venous catheter (odds ratio, 4.6; 95% confidence interval, 1.8 to 11.8).

We observed changes in clinical obstetric and neonatal care that paralleled the increase in GNR bacteremia at our institution. A prospective study is needed to elucidate the impact of these changes on the incidence of GNR bacteremia in this population.