Neonatal Sepsis Epidemiology at a Major Public Hospital in Mexico City

This study aimed to describe the epidemiology, pathogens, and outcomes associated with early-onset and late-onset sepsis among newborns admitted to the leading public neonatal hospital in Mexico.We conducted a retrospective cohort study of infants admitted to the neonatal intensive care unit (NICU) at the Instituto Nacional de Perinatología in Mexico City from 2018 to 2023. Early-onset sepsis (EOS) was defined as a culture-confirmed bacterial infection of blood or cerebrospinal fluid within 3 days of birth, and late-onset sepsis (LOS) as culture-confirmed bacterial or fungal infection after day 3. Descriptive statistics and logistic regression were used to compare characteristics and outcomes among infants with and without EOS/LOS.Among 4,381 admitted infants, 23 (0.5%) had EOS (5.2 per 1,000 admissions), and 444 of 3,950 (11.2%) who survived >3 days had LOS (112.4 per 1,000). Prematurity was a major risk factor. <i>Escherichia coli</i> accounted for 70% of EOS, and coagulase-negative staphylococci and <i>Klebsiella</i> spp. were the leading causes of LOS. Infections were associated with higher morbidity, longer hospitalization, and reduced survival, though mortality differences were not statistically significant after adjustment.Neonatal sepsis remains a major burden in this Mexican NICU, with a predominance of gram-negative organisms and incidence rates higher than recent U.S. reports. Continued surveillance and antimicrobial stewardship are warranted to guide empiric therapy and track resistance patterns. · Prematurity was a major risk factor for both early- and late-onset sepsis.. · Gram-negative organisms, especially Escherichia coli and Klebsiella species, were the predominant pathogens.. · Sepsis was associated with increased morbidity, prolonged hospitalization, and lower survival..