Very low birth weight preterm infants with early onset neonatal sepsis: the predominance of gram-negative infections continues in the National Institute of Child Health and Human Development Neonatal Research Network, 2002-2003.

BACKGROUND: Early onset neonatal sepsis (EOS, occurring in the first 72 hours of life) remains an important cause of illness and death among very low birth weight (VLBW) preterm infants. We previously reported a change in the distribution of pathogens associated with EOS from predominantly gram-positive to primarily gram-negative organisms.

OBJECTIVE: To compare rates of EOS and pathogens associated with infection among VLBW infants born at centers of the National Institute of Child Health and Human Development (NICHD) Neonatal Research Network during 3 time periods: 1991-1993; 1998-2000; and 2002-2003.

STUDY DESIGN: Prospectively collected data from the NICHD Neonatal Research Network VLBW registry were retrospectively reviewed. Rates of blood culture confirmed EOS, selected maternal and infant variables and pathogens associated with infection were compared between 2002-2003 and 2 previously published cohorts.

RESULTS: During the past 13 years, overall rates of EOS have remained stable (15-19 per 1000 live births of infants 401-1500 g). More than one-half of early infections in the 2002-2003 cohort were caused by gram-negative organisms (53%), with Escherichia coli the most common organism (41%). Rates of group B streptococcal infections remain low (1.8 per 1000 live births). Between 1991-1993 and 1998-2000, there was a significant increase in rates of E. coli infections; but in 2002-2003, there was no significant change (7.0 per 1000 live births). Infants with EOS continue to be at significantly increased risk for death compared with uninfected infants.

CONCLUSION: EOS remains an uncommon but important cause of morbidity and mortality among VLBW infants. Gram-negative organisms continue to be the predominant pathogens associated with EOS.