European Journal of Cardiovascular Medicine

Neonatal sepsis is defined as systemic bloodstream infection occurring within the first 28 days of life and remains a leading cause of neonatal mortality. Early-onset sepsis is associated with maternal and perinatal risk factors, while late-onset sepsis is often hospital-acquired. Compared to developed countries, the spectrum of microbiological pathogens associated with neonatal sepsis in developing countries is distinct with gram negative organisms making up majority of the cases. Understanding clinical features and pathogen profiles is critical for early diagnosis and optimal management.

Aims and Objectives

Aim: To evaluate the clinical profile, laboratory determinants, and bacteriological spectrum of neonatal sepsis in a tertiary care centre.

Objectives:

1) To assess risk factors associated with neonatal sepsis.

2) To assess the clinical profile, common organisms, laboratory determinants of neonatal sepsis.

This prospective observational study was conducted among 400 neonates admitted with suspected or confirmed sepsis to the NICU at HIMS Hassan between January 2024 and December 2024. Clinical symptoms, laboratory investigations, and blood culture results were analyzed. Neonates with birth weight (<1000g) and obvious malformations/congenital anomalies were excluded. Descriptive statistics were used.

Among the 400 neonates admitted with sepsis , early-onset sepsis accounted for 54% of cases whereas late onset sepsis accounted for 46 % of the cases. Among the risk factors, low birth weight and prematurity was the most common (76.25%) followed by birth asphyxia (30%) , prolonged labor (17.7%), meconium stained liquor (15.25%) and premature rupture of membranes(14.75%).

With respect to clinical presentation, respiratory distress (64.75%), shock (57%), convulsions (57%) and lethargy (56.25%) were the most common presenting features followed by temperature instability (34%) and abdomen distension (31%).

With respect to total Leukocyte count, leukopenia was found in 48% of cases and leukocytosis in 10% cases. Absolute neutrophil count was deranged in 22% in which neutropenia was observed in 1.5% and neutrophilia was found in 19.7%. CRP was elevated in 84% and NLR in 66.75% . Abnormal peripheral smear (shift to left, toxic granules, vacuolations) was found in 29.5% cases. Blood culture was positive in 27%, with Acinetobacter baumannii, Klebsiella pneumoniae, and Staphylococcus aureus being common isolates. CSF proven meningitis was found in 2.75% cases.

Neonatal sepsis continues to pose a significant diagnostic challenge due to its heterogeneous clinical presentation, rapid progression, and the influence of perinatal and maternal factors. In the present study, Early-Onset Sepsis (EOS) constituted 54% of cases, which is consistent with the findings of Purushottam P. Rahi et al1. and Xiaoxia Li et al.2 This predominance highlights the critical role of maternal and intrapartum determinants in the pathogenesis of neonatal sepsis, emphasizing the need for precise perinatal monitoring and timely obstetric intervention.

A substantial proportion of affected neonates (76.25%) were either low birth weight or premature, corroborating observations from Edwardo Rubio et al.3 and Das et al.4 This reinforces the immaturity of immune system of premature neonates. Similarly, maternal risk factors such as prolonged labor (17.7%), premature rupture of membranes (14.75%), and meconium-stained amniotic fluid (15.2%) demonstrated results comparable to those reported by Tsai M. et al.5 and Melesse et al.6, suggesting that obstetric complications remain important contributors to neonatal infectious morbidity.

Clinically, respiratory distress was the most frequent manifestation (64.75%), followed by shock/convulsions (57.75%) and lethargy (56.25%), findings similar to reports by Veereswara Rao et al.7 and Jajoo et al.8 These nonspecific manifestations underscore the importance of early screening tools for diagnosis.

Hematological parameters revealed leukopenia in 48% and leukocytosis in 10% of cases, reflecting trends described by Guo J. et al9 and Adane T. et al10. Derangements in absolute neutrophil count were detected in 22% of neonates, with neutropenia and neutrophilia observed in 1.5% and 19.7%, respectively, consistent with the findings of Chowdhury R. et al.11 and Kumari S. et al.12 Elevated C-reactive protein levels were present in 84% of neonates, aligning with studies by Shazia Naz et al.13 and Mehrotra G. et al.,14 suggesting that CRP remains a valuable adjunctive marker in sepsis evaluation, particularly in resource-limited settings. Additionally, the neutrophil-to-lymphocyte ratio was increased in 66.75% of cases, corroborating the reports of Ozdemir et al.15 and Al Nady et al.16, further supporting its potential utility as an accessible inflammatory indicator.

Thrombocytopenia, identified in 65.25% of neonates, was comparable to the observations of Hafza Malik et al.17 and Charoo B. et al.18, Abnormal peripheral smear findings (29.5%) also showed considerable similarity to reports by Amber S. et al.19 and Saied D. A. et al.20, implying that morphological changes in blood cells may offer supportive diagnostic insight. Blood culture positivity was documented in 27% of cases with predominant gram negative bacteremia , which aligns with rates reported by Mohakud et al.21 and Raju et al.22, acknowledging the need of knowing bacteriological spectrum of neonatal sepsis in an area for prompt treatment . Cerebrospinal fluid analysis confirmed meningitis in 2.75% of neonates, consistent with the findings of Mathew J. et al.23 and Wondimu M. N. et al.24, highlighting the need for selective but timely lumbar puncture in suspected cases.

Overall, the findings of this study demonstrate strong concordance with existing literature and reaffirm the multifactorial nature of neonatal sepsis, wherein clinical, maternal, and laboratory variables collectively influence disease onset and progression. The predominance of EOS and the high burden of prematurity and low birth weight underscore the importance of perinatal risk reduction strategies. Furthermore, the constellation of hematological abnormalities—including elevated CRP, altered WBC indices, and thrombocytopenia—supports their continued relevance as diagnostic adjuncts in neonatal sepsis evaluation.

The present study highlights that neonatal sepsis continues to be a major clinical burden, with diverse risk factors and laboratory abnormalities. The predominance of low birth weight and prematurity as major contributors emphasizes the need for strengthened perinatal care and early risk identification. Laboratory parameters such as CRP, NLR, leukocyte indices, and peripheral smear changes demonstrated significant diagnostic value, reinforcing their role in the early evaluation of suspected cases. The bacteriological profile, dominated by gram negative bacteremia in this study, underscores the importance of institution-specific antibiotic stewardship. Despite advancements, the observed mortality rate underscores the need for timely diagnosis, appropriate antimicrobial therapy, and improved preventive strategies to reduce the burden of neonatal sepsis. Figures Figure 1: Distribution of Age at Onset Figure 2: Maternal Risk Factors Figure 3: Neonatal Risk Factors Figure 4: Bacteriological Spectrum Figure 5: Blood Investigation Abnormalities Limitations of the study 1. Limited Long-Term Outcome Data: The study does not include long-term neurodevelopmental or health outcomes of surviving neonates, which are important for assessing sepsis impact. 2. Potential for Selection Bias: Only inborn and admitted neonates were included, possibly excluding milder cases or those presenting to peripheral centers

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