MRSA nasal screening predictive values assessment in patients with osteomyelitis

Area of Science:

• Infectious Diseases
• Clinical Microbiology
• Orthopedic Surgery

Background:

• Osteomyelitis is a serious bone infection often caused by Staphylococcus aureus.
• Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant treatment challenge.
• Accurate and timely diagnosis is crucial for effective management of MRSA osteomyelitis.

Purpose of the Study:

• To evaluate the diagnostic accuracy of methicillin-resistant Staphylococcus aureus (MRSA) nasal screening via polymerase chain reaction (PCR) assays.
• To determine the value of MRSA nasal PCR in predicting MRSA osteomyelitis.
• To assess the impact of MRSA nasal PCR on clinical outcomes, including antibiotic therapy duration.

Main Methods:

• A retrospective chart review of 107 adult patients with osteomyelitis was conducted.
• MRSA nasal PCR results were compared with culture data for concordance.
• Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated.

Main Results:

• The MRSA nasal PCR demonstrated a high NPV of 94.7% (CI: 91.29-96.87%).
• The PPV was found to be low at 25% (CI: 10.08-49.79%).
• Patients negative for MRSA by nasal PCR had a shorter duration of anti-MRSA therapy.

Conclusions:

• MRSA nasal PCR screening has a high NPV, making it useful for ruling out MRSA osteomyelitis.
• The low PPV indicates that a positive nasal PCR result alone is insufficient to confirm MRSA osteomyelitis.
• Early de-escalation of antibiotic therapy was observed, suggesting potential clinical utility despite limitations.