Meticillin-resistant Staphylococcus aureus Contact Screening Strategy in a Low Prevalence Setting; a Nested...

Area of Science:

• Infectious Diseases
• Hospital Epidemiology
• Microbiology

Background:

• Meticillin-resistant Staphylococcus aureus (MRSA) poses a significant healthcare challenge.
• Optimal screening strategies for secondary MRSA cases in low-prevalence hospital settings are not well-defined.
• Identifying factors associated with documented MRSA transmissions is critical for effective infection control.

Purpose of the Study:

• To identify factors associated with documented MRSA transmissions.
• To evaluate the effectiveness of a hospital-wide MRSA screening strategy.
• To determine optimal screening approaches in low-prevalence settings.

Main Methods:

• Retrospective, nested case-control study conducted in a 950-bed tertiary care hospital (2008-2014).
• Screening of room and ward contacts of MRSA index patients.
• Comparison of Staphylococcus aureus Protein A (spa)-type matched contact patients (cases) with controls (negative or spa-type mismatched).

Main Results:

• A total of 215 MRSA screenings identified 3013 contact patients; only 6 (0.2%) spa-type matched pairs were found.
• Cases were more frequently associated with 'same room' contact (P=0.001) and longer exposure times (median 6 days vs. 1 day, P=0.016) compared to controls.
• The extensive screening strategy yielded limited index/contact matches via spa-typing.

Conclusions:

• Prolonged exposure time and sharing a room are significant risk factors for MRSA transmission.
• An extensive MRSA screening strategy is inefficient in low-prevalence settings.
• A targeted screening approach may be more effective than screening entire wards for MRSA detection.