Reliability of Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal Swab Screening for Predicting MRSA Burn...

Area of Science:

• Infectious Diseases
• Burn Care
• Microbiology

Background:

• Infections are a leading cause of mortality in burn patients, with soft tissue infections being a significant source of sepsis.
• Methicillin-resistant Staphylococcus aureus (MRSA) is prevalent in burn units, often necessitating empiric vancomycin treatment.
• Nasal swab screening for MRSA colonization aids in infection control and decontamination strategies.

Purpose of the Study:

• To evaluate the utility of MRSA nasal swab screening in predicting MRSA presence in burn wound cultures.
• To determine the diagnostic accuracy of MRSA nasal swabs for infected burns.

Main Methods:

• Retrospective review of 250 burn patients undergoing weekly MRSA nasal swab screening and developing infections over 36 months.
• Comparison of nasal swab results with bacterial cultures from infected burn wounds.
• Calculation of test performance metrics: sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

Main Results:

• MRSA nasal swabs demonstrated a sensitivity of 64.1%, specificity of 96.2%, PPV of 75.8%, and NPV of 93.5%.
• Nasal swabs were more sensitive in predicting community-acquired MRSA infections (66.7% positive) than hospital-acquired infections (55.6% positive).
• A negative nasal swab result indicates a low likelihood of MRSA-caused burn infections.

Conclusions:

• MRSA nasal swab screening is a valuable tool for predicting MRSA in burn wound infections.
• The high NPV supports de-escalating MRSA antibiotic coverage in patients with negative nasal swab results.
• Universal MRSA nasal screening should be implemented in burn centers to guide antimicrobial therapy decisions.