A ten-year retrospective study on the clinical and microbiological characteristics of early onset neonatal sepsis at a single tertiary care institution

Introduction: Early onset neonatal sepsis (EOS) remains a significant cause of morbidity and mortality globally. The most common etiologic agent for EOS was known to be Group B Streptococcus (GBS) and Escherichia coli. However, causative pathogens and its antibiotic susceptibility can vary per institution creating a challenge in management and empirical treatment. Understanding the epidemiology, clinical characteristics, microbiological profile, and outcomes of neonatal sepsis in a single center study is crucial to improve diagnosis, treatment, and prevention strategies.

Objectives: This study aimed to characterize demographic, clinical, and microbiological features of neonates with early onset neonatal sepsis, evaluate antimicrobial susceptibility patterns, and assess temporal trends and clinical outcomes over a ten-year period from 2015 to 2024. By doing so, this can promote quality of neonatal care within this institution and similar healthcare environments. 

Methods: A retrospective cohort study was conducted at a private tertiary institution including 409 neonates diagnosed with early onset neonatal sepsis. Data on demographic variables, clinical signs and symptoms, maternal and perinatal risk factors, laboratory and microbiological findings, antimicrobial susceptibility, and clinical outcomes were collected. Annual trends of culture-positive versus culture-negative sepsis cases were analyzed. Statistical tests including chi-square, t-tests, were utilized.

Results: Culture-positive neonates had significantly lower birthweight and gestational age. Tachypnea and temperature instability were prevalent clinical signs. A larger proportion of culture negative group were asymptomatic. (20.8% vs 6.3%). Premature rupture of membranes remained to be most documented risk factor. Gram-positive bacteria, namely Methicillin-resistant Staphylococcus epidermidis constituted majority of the isolates. This contrast to the known common agents for EOS of GBS. Escherichia coli was the most common Gram-negative pathogen but occurs less frequently. CRP showed superior discriminative value in distinguishing culture-positive sepsis, while leukopenia rather than leukocytosis is a more relevant indicator for sepsis. There was a high level of resistance to beta lactam antibiotics (Cefoxitin, Oxacillin) among gram-positive organisms. Vancomycin and Linezolid retained high efficacy against such resistant organisms. Gram-negative isolates remained highly susceptible to the commonly utilized Amikacin and Piperacillin-Tazobactam. Culture-positive sepsis was associated with higher mortality (4.2%). Temporal analysis revealed a stable rate of culture-positive sepsis and did not exhibit a significant secular trend over the study period.

Conclusion: Early onset Neonatal sepsis in this population is marked by vulnerability related to prematurity and low birthweight, diverse clinical presentations, and multidrug-resistant pathogens. Integrated surveillance, tailored antimicrobial stewardship, and targeted preventive strategies are essential to reduce sepsis burden and improve neonatal outcomes.

Dr. Vilma Antonette Prado is currently a third-year Pediatric assistant Chief Resident at Chong Hua Hospital, Cebu. She graduated with a degree in Medical Technology at Velez College and garnered her medical degree at the Cebu Institute of Medicine, wherein she ranked third in her class out of 157 students. Her recent achievements include being awarded the Global Resident onsite Scholarship award at Boston Children’s Hospital, and winning the Cebu chapter Nephrology Quiz bowl.