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. Escherichia coli accounted for 70% of EOS, and coagulase-negative staphylococci and Klebsiella 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..