Risk of methicillin-resistant Staphylococcus aureus surgical site infection in patients with nasal MRSA colonization

Area of Science:

• Infectious Diseases
• Surgical Outcomes
• Healthcare Epidemiology

Background:

• Patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) face an elevated risk of invasive infections.
• The specific risk of MRSA surgical site infection (SSI) among carriers remains unclear, necessitating further investigation for effective prevention strategies.

Purpose of the Study:

• To assess the incidence of MRSA SSI in patients screened for MRSA colonization.
• To identify risk factors associated with MRSA SSI in surgical patients.

Main Methods:

• A retrospective cohort study was conducted involving inpatients screened for MRSA nasal colonization via PCR prior to a surgical procedure.
• Data were collected from April 2008 to July 2010 at a tertiary care center.

Main Results:

• The incidence of MRSA SSI was 1.86% in MRSA PCR-positive patients versus 0.20% in MRSA PCR-negative patients.
• MRSA PCR-positive status was an independent risk factor for MRSA SSI (OR, 9.20; P < .0001).
• Other identified risk factors included prolonged surgery duration (≥137 minutes), higher American Society of Anesthesiologists score (≥3), and abdominal surgery.

Conclusions:

• Surgical patients with positive nasal MRSA PCR screening demonstrated a nine-fold increased odds of developing MRSA SSI.
• Despite the increased odds, the overall incidence of MRSA SSI in PCR-positive patients was low (1.86%).
• Targeting decolonization and other interventions toward high-risk patient subsets may optimize SSI prevention efforts.