Epidemiology of bacterial bloodstream infections in very low birth weight neonates at Charlotte Maxeke Johannesburg Academic Hospital

Abstract

Abstract: Introduction: Very low birth weight (VLBW) neonates are at a higher risk of neonatal sepsis because of immature immune systems and prolonged hospitalisation. The pattern of causative pathogens changes with time therefore frequent surveillance remains essential.
Objectives: To review bacterial organisms causing bloodstream infections and their associated antimicrobial susceptibility pattern.
Methods: A retrospective observational study between 1st January 2016 and 31st December 2016 was conducted. The study population included all VLBW neonates with blood culture-proven infection who were admitted to the neonatal unit at Charlotte Maxeke Academic Johannesburg Hospital (CMJAH).
Results: A total of 479 neonates were admitted to the NICU. There were 206 episodes of infection in 173 of the neonates (36.1%); 184 (89.23%) episodes of sepsis were culture proven late-onset sepsis (LONS) and 22 (10.7%) were culture proven early-onset sepsis (EONS). Gram-positive organisms accounted for the majority of isolates (64.1%) with coagulasenegative Staphylococci (CoNS) being the commonest pathogen in EONS at 68% and LONS at 35% respectively. The retrospective
nature of the study meant that it was not possible to determine if CoNS were contaminants or pathogens. There was no case of
Streptococcus agalactiae in the EONS. The number of multidrugresistant organisms was more common in LONS than EONS
with extended beta-lactamase producers in 20% of gram negatives.
The majority of S. aureus isolated in LONS were methicillin resistant Staphylococcus aureus (MRSA). Accordingly, the overall susceptibility to the first-line antimicrobials is low.

Conclusion: The current first-line therapy does not provide adequate cover. There is poor susceptibility to ampicillin by most pathogens but it remains an antibiotic of choice for EONS. LONS is still more predominant than EONS. Meropenem and vancomycin are suitable options for LONS.