Understanding Neonatal Sepsis: Infection Foci and Risk Profiles in Preterm and Term Infants

Background/Objectives: Neonatal sepsis remains a major contributor to neonatal morbidity and mortality worldwide, yet diagnostic uncertainty and heterogeneous clinical presentation continue to challenge early recognition and management. Early onset sepsis (EOS), typically arising within the first 72 hours of life, is strongly influenced by maternal and perinatal factors. Limited data exist on the temporal evolution of infec-tion foci during the first week of life. Methods: To identify the predominant infection localization sites in preterm and term neonates with suspected or confirmed sepsis and to determine maternal and neonatal risk factors associated with early disease severity, persistent sepsis, and adverse outcomes .Results: A total of 297 neonates met inclusion criteria. Most infants (99.3%) were admitted before 72 hours of life. Respiratory involvement was the predominant infection focus on Day 1 (57.2%) and remained common through Day 3. CNS, gastrointestinal, and skin involvement were infrequent. Lower gestational age (p=0.035) and pro-longed rupture of membranes >18 hours (p=0.043) independently predicted sepsis at Day 1. Advanced sep-sis at admission was associated with lower birth weight, lower gestational age, older maternal age, and ab-sence of intrapartum antibiotics (all p≤0.001). Persistent sepsis at Day 7 was linked to prematurity (p=0.008), higher mortality (p< 0.001), and prolonged hospitalization (p=0.001). Conclusions: Respiratory involvement is the most common early infection focus in neonates with EOS. Prematurity, low birth weight, prolonged rupture of membranes, and maternal intrapartum infection significantly increase the risk of severe disease.