In this observational study, the NICHD Neonatal Research Network (NRN) is conducting surveillance of all infants born at NRN centers to identify all newborns who are diagnosed with early-onset sepsis (EOS) and/or meningitis. The study will: establish current hospital-based rates of EOS among term and preterm infants in the era of intrapartum antibiotic prophylaxis; monitor the organisms associated with EOS and meningitis; compare asymptomatic and symptomatic infants by gestational age and pathogen; and monitor sepsis-associated mortality rates by pathogen group.

For more than a decade, the NICHD Neonatal Research Network (NRN) has conducted surveillance of early-onset sepsis (EOS) infections in very low birth weight (VLBW) infants, as part of its very low birth weight registry. Although overall rates of EOS have remained stable over time, the relative importance of different pathogens has changed.

In 2002 the American Academy of Pediatrics, the American College of Obstetricians and Gynecologists, and the Centers for Disease Control & Prevention revised their recommendations for reducing mother-to-child transmission of group B streptococcal (GBS) infections. The new guidelines recommend universal screening of pregnant women at 35 or more weeks' gestation and intrapartum antibiotics for all GBS-colonized mothers (an estimated 30% of mother-to-be in the United States). With the current widespread use of maternal antibiotics, concerns have been raised about the possible emergence of non-GBS pathogens as causes of early-onset sepsis. Several studies have reported a change in EOS pathogens, with the emergence of gram-negative and antibiotic-resistant infections, primarily among VLBW infants.

This observational study expands the NRN's prior work on infection in VLBW infants, conducting surveillance of all infants born at network centers who are diagnosed with early-onset sepsis and/or meningitis. The study will: establish current hospital-based rates of EOS among term and preterm infants in the era of intrapartum antibiotic prophylaxis; monitor the organisms associated with EOS and meningitis; compare asymptomatic and symptomatic infants by gestational age and pathogen; and monitor sepsis-associated mortality rates by pathogen group. Cases will be identified by the medical care team or through research team review of patient, microbiology, or infection control/hospital epidemiology records.

Secondary analyses include:

Serotypic, phylogenetic, virulence and drug-resistance characteristics of contemporary GBS and E. Coli isolate collections will be studied.

Assessing the proportion of neonates born to mothers with chorioamnionitis who are asymptomatic at birth, but later develop signs and/or symptoms of early-onset neonatal GBS and non-GBS disease.

Inclusion Criteria:

• Infants >400g birth weight

Exclusion Criteria:

• Stillbirth or death in the delivery room

All live born infants >400g birth weight delivered at NICHD Neonatal Research Network participating hospitals