[Epidemiological study on nasal carriage in hospitalized children infected with Staphylococcus aureus]

Area of Science:

• Pediatric Infectious Diseases
• Clinical Microbiology
• Hospital Epidemiology

Background:

• Staphylococcus aureus (S. aureus) is a common cause of hospital-acquired infections.
• Nasal carriage of S. aureus is a known reservoir for infection.
• Understanding the link between nasal carriage and infection is crucial for infection control.

Purpose of the Study:

• To investigate the association between S. aureus nasal carriage and active S. aureus infection in hospitalized children.
• To determine the prevalence of S. aureus nasal carriage in this population.
• To assess the characteristics of S. aureus strains, including methicillin resistance and virulence factors.

Main Methods:

• Recruitment of 56 hospitalized children with S. aureus infection.
• Collection and culture of nasal swabs to determine S. aureus nasal carriage rates.
• Polymerase chain reaction (PCR) to detect the PVL virulence gene and mecA resistance gene in both clinical and nasal carriage isolates.

Main Results:

• 39% of hospitalized children (22/56) were nasal carriers of S. aureus, with a higher prevalence in infants under one year.
• Methicillin-resistant S. aureus (MRSA) rates were 29% in infected strains and 32% in carriage strains.
• mecA gene presence was consistent between clinical and nasal carriage isolates; PVL-positive carriage strains were frequently MRSA and matched clinical isolates.

Conclusions:

• Nasal carriage of S. aureus is a significant risk factor for developing S. aureus infections in hospitalized children.
• Nosocomial transmission likely contributes to nasal carriage, which can subsequently lead to infection.
• The high isolation rate of MRSA underscores the need for enhanced surveillance and infection control measures for S. aureus in pediatric hospital settings.