Pathogen-specific early mortality in very low birth weight infants with late-onset sepsis: A national survey

Background. Late-onset sepsis ( LOS) is an important cause of mortality among very low birth weight ( VLBW) infants, and deaths occurring within 3 days after the onset of sepsis can probably be ascribed to sepsis. We examined the association of sepsis due to specific pathogens with the risk for early mortality after the onset of LOS, adjusted for perinatal and neonatal risk factors. Methods. From 1995 through 2001, information about 10,215 infants was gathered and deposited in the Israel National VLBW Infant Database. The study population was composed of 2644 infants, of which each had greater than or equal to1 events of LOS (totalling 3462 events). Logistic regression models were used to calculate the crude and adjusted risk for early mortality. Results. Early mortality was associated with 179 LOS events (5.2% of 3,462); the range of pathogens associated with these events included coagulase-negative staphylococci (CoNS), which were the cause of 1.8% of LOS events associated with early mortality, and Pseudomonas species, which were the cause of 22.6% of such events. Early mortality after LOS, adjusted for neonatal risk factors, was significantly associated with sepsis due to certain pathogens: Pseudomonas species (odds ratio [ OR], 12.3); Klebsiella species (OR, 6.3); Serratia species (OR, 6.2); Escherichia species (OR, 4.3); Enterobacter species (OR, 4.1); and Candida species (OR, 3.2), compared with sepsis due to CoNS. In addition, lower gestational age, lower chronological age, small size for gestational age, and grade 3-4 intraventricular hemorrhage, each had an independent association with early mortality. Conclusions. Klebsiella sepsis and Pseudomonas sepsis were associated with a 6.3-fold and 12.3-fold increased risk of early mortality, respectively, and accounted for 41.9% of all early deaths associated with LOS. Considering the aggressive nature of sepsis caused by these pathogens, empiric antibiotic therapy active against these organisms is worth consideration for VLBW infants with presumed LOS.