Pediatric Staphylococcus aureus Infections: Impact of Methicillin Resistance at a Canadian Center.

Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) causes a wide spectrum of potentially serious infections in children. This study describes the evolving experience with S. aureus infections at a Canadian tertiary pediatric care center serving a wide geographic area. Design: In this two-component study, a retrospective review of infection control databases for MRSA infection was conducted, along with a prospective component for 1 year during which all community-onset S. aureus infections were identified. Cases with methicillin resistance and susceptibility were compared. Results: Review of infection control database records showed 239 unique infections, with steady increases over time. Common pulsed-field gel electrophoresis types included Canadian MRSA-7 and Canadian MRSA-10. During the 1-year prospective component, 210 clinical infections were identified, with MRSA isolated in 41%. Patients with MRSA were significantly younger than those with methicillin-susceptible isolates (4.9 vs 7.7 years, P < 0.001). The most common presentations were soft tissue infections in the emergency department, with a degree of inappropriate antimicrobial use. Conclusions: MRSA contributed to a significant proportion of S. aureus infections at a large Canadian tertiary care center. Ample opportunities exist to develop stewardship protocols, especially for the management of soft tissue infections in outpatients.