2026 Eastern States Conference

Authors 
Joanna Nguyen, PharmD; Annie Jeon, PharmD, BCPS; Lina Saliba, PharmD, BCPS, BCCCP; Jenna Smith, PharmD, BCCCP; Lois Lee, PharmD, BCPPS, BCIDP  
 
Learning objective
Describe how rapid PCR-based MRSA screening helps support antimicrobial stewardship compared to culture-based screening 
 
Background/Objective 
This study aims to compare the impact of rapid PCR-based versus culture-based MRSA screening on antibiotic stewardship outcomes, primarily vancomycin duration of therapy in hospitalized patients. 
 
Methods 
This retrospective chart review compared outcomes between culture-based (May-November 2024) and PCR-based (January-June 2025) MRSA screening following institutional implementation of the latter in December 2024. Eligible patients received at least one vancomycin dose with MRSA screening ordered within 48 hours of vancomycin initiation; patients were excluded for age under 18 years, death or transfer out of the hospital during active therapy, vancomycin for non-MRSA indications, or vancomycin therapy prior to admission. Primary outcome was vancomycin duration (reported as median with interquartile range and analyzed using Mann-Whitney U test); secondary outcomes included test turnaround time, test concordance rates, and vancomycin continuation from the Emergency Department (ED) into hospital admission. 
 
Results 
A total of 167 patients were included. Median vancomycin duration was significantly shorter in the PCR-based group compared to the culture-based group (1 vs. 3 days, p < 0.001). Turnaround time to final result was 5 vs. 29 hours from order entry and 2 vs. 26 hours from specimen collection for PCR-based and culture-based screening, respectively. The majority of test results were true negatives; false positives occurred in 13% of PCR-based and 7% of culture-based screenings. Among 40% of patients who received initial vancomycin in the ED, concurrent MRSA screening was ordered in only 59% (PCR-based) and 33% (culture-based) of these patients. Vancomycin was continued at hospital admission in up to 93% of patients. 
 
Conclusion 
PCR-based MRSA screening significantly reduced vancomycin therapy duration through rapid results and expedited de-escalation. ED screening rates remained suboptimal despite high vancomycin initiation in this population, representing an intervention opportunity. Future directions include expanding this study across the health system, optimizing timing and ordering of screening through standardized ED protocols, and educating clinical staff on PCR-based screening utility for de-escalation. 
 
Self-assessment question:  
Based on the study findings, which of the following statements regarding MRSA screening is most accurate? 
A.  PCR-based MRSA screening significantly reduced vancomycin duration of therapy compared to culture-based screening, because it demonstrated substantially higher true negative rates. 
B. PCR-based MRSA screening significantly reduced vancomycin duration of therapy compared to culture-based screening, primarily due to faster test turnaround time. 
C. PCR-based MRSA screening provided similar vancomycin duration outcomes compared to culture-based screening. 
D. PCR-based MRSA screening significantly reduced vancomycin duration of therapy compared to culture-based screening by decreasing the frequency of empiric vancomycin initiation.