Staphylococcus aureus infections in Australasian neonatal nurseries

Area of Science:

• Neonatal infections
• Bacterial sepsis
• Public health microbiology

Background:

• Neonatal nurseries face challenges with bacterial infections.
• Staphylococcus aureus, including methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) strains, can cause severe neonatal sepsis.
• Understanding the epidemiology and outcomes of these infections is crucial for prevention and treatment.

Purpose of the Study:

• To investigate the incidence and outcomes of systemic Staphylococcus aureus infections in Australasian neonatal units.
• To compare the characteristics and mortality rates of MSSA and MRSA neonatal sepsis.
• To identify risk factors and trends in S. aureus neonatal infections.

Main Methods:

• A prospective longitudinal study was conducted across 17 Australasian neonatal nurseries.
• Systemic infections were defined as clinical sepsis with positive blood and/or cerebrospinal fluid cultures.
• Data on incidence, infant characteristics, and mortality were collected and analyzed.

Main Results:

• The incidence of early-onset S. aureus sepsis was low (0.08 per 1000 live births), primarily caused by MSSA.
• An MRSA outbreak occurred in Melbourne, successfully managed with topical mupirocin and enhanced hand hygiene.
• Infants with MRSA sepsis were smaller and more preterm than those with MSSA sepsis, with higher mortality (24.6% vs. 9.9%).
• Early-onset MSSA sepsis exhibited a particularly high mortality rate (39%).

Conclusions:

• Staphylococcus aureus is an uncommon but significant pathogen in early-onset neonatal sepsis.
• While late-onset MRSA infections have higher mortality than late-onset MSSA, early-onset MSSA sepsis presents a critical threat.
• Effective infection control measures, including hygiene and targeted antimicrobial use, are vital in neonatal settings.