Change in Methicillin-Resistant Staphylococcus aureus Testing in the Intensive Care Unit as an Antimicrobial...

Area of Science:

• Infectious Diseases
• Clinical Microbiology
• Healthcare Quality Improvement

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) infections pose significant morbidity and mortality risks in intensive care units (ICUs).
• Vancomycin is a primary treatment for MRSA but carries inherent risks and requires careful management.

Purpose of the Study:

• To evaluate the impact of switching MRSA diagnostic methodology from culture to PCR on time to results in adult ICUs.
• To assess the effect of accelerated MRSA test results on antimicrobial stewardship practices.

Main Methods:

• A change in MRSA testing strategy from culture to PCR was implemented across two ICUs (tertiary and community) within a Midwestern US health system.
• Data from 2016-2020 were analyzed, focusing on the median change in time to obtain MRSA test results before and after the intervention.

Main Results:

• MRSA testing was performed on 71% of 19,975 ICU patients during the study period.
• The implementation of PCR testing led to a significant reduction in time to results, with estimated savings of 36 and 32 hours at the tertiary and community hospitals, respectively.
• Culture-based testing decreased dramatically post-intervention, becoming nearly obsolete.

Conclusions:

• The transition to PCR-based MRSA testing substantially decreased the time required to obtain results in ICUs.
• Expedited MRSA test results support antimicrobial stewardship by enabling timely initiation or de-escalation of therapies like vancomycin.