 This observational study expands the NRNs prior work on infection in VLBW infants, conducting surveillance of all infants born at network centers who are diagnosed with early-onset sepsis andor 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 controlhospital epidemiology records. 