Background Sepsis is a major cause leading to neonatal mortality and morbidity, particularly for tiny preemies. The purpose of this study aimed to compare outcome between infants with birth weight (BBW)≤750 g having culture-positive sepsis and infants without any positive culture.

Methods This was a retrospective cohort study of infants with BBW≤750 g admitted to Chang Gung Children’s Hospital between January 2006 and December 2010. Sepsis was defined as infants had clinical signs and positive blood culture results. Outcome, pathogens and clinical data were collected.

Results 154 infants were enrolled; the gestational age (GA) and BBW were 25.1±1.9 weeks and 639.6±88.5 g (mean±SD), respectively. 46 patients (29.9%) had sepsis and the incidence of sepsis was 5.2 episodes per 1000 patient days. There were 62 episodes of sepsis involving 66 pathogens during the study period. 38 gram-positive pathogens (57.6%), 22 gram-negative pathogens (33.3%) and 6 fungal infection (9.1%) were identified. The major causative pathogens were coagulase negative staphylococcus (n=24), Escherichia coli (n=7) and klebsiella pneumoniae (n=7). Infants received patent ductus arteriosus ligation or had retinopathy of prematurity requiring therapy were associated with developing sepsis thereafter. There was no significant difference in GA, BBW, gender, Apgar scores, intraventricular hemorrhage, bronchopulmonary dysplasia and mortality between sepsis and non-sepsis groups. The mortality rate was 42.9%, and sepsis related mortality accounted for 14.5% of mortality in the current study.

Conclusions One third of infants with BBW≤750 g had sepsis. Based on the finding of identified pathogens, nosocomial infection was still the major cause for sepsis.