Fast track SSTI management program based on a rapid molecular test (GeneXpert® MRSA/SA SSTI) and antimicrobial stewardship

Abstract

Purpose: This study examines the impacts of a skin and soft tissue infection (SSTI) management program involving a rapid diagnostic algorithm (Gram stain plus real-time PCR, GeneXpert® MRSA/SA SSTI) performed directly on clinical samples plus antimicrobial stewardship (AMS) counseling of the responsible physician.

Methods: Participants were 155 consecutive adult inpatients with SSTI and good quality clinical samples submitted to the microbiology laboratory from April 2016 to January 2017. Results of the rapid test and AMS recommendations were phoned through to the responsible physician. The comparison group was a historical cohort.

Results: Most SSTI were surgical wound infections (41.3% vs 38.1% for the intervention and comparison groups respectively) followed by diabetic foot (14.2% and 18.1%), abscesses (13.5% both) and cellulitis (12.9% both). Isolated microorganisms were mostly Gram-negative bacilli (two-thirds), followed by Staphylococcus aureus (SA). The ratio methicillin-susceptible SA (MSSA) to methicillin-resistant SA (MRSA) was 4:1. Improvements in the intervention cohort were: DOT (22.0 vs. 24.3 days, p = 0.007), treatment duration per SSTI episode (14.1 vs. 15.0 days, p = 0.072), treatment cost (433.1 vs. 533.3 €, p = 0.039), length of stay (18.6 vs 20.7 days, p = 0.031), related mortality (1 vs. 4 patients, p = 0.022) and Clostridium difficile infection (CDI) (4 vs. 8 patients, p = 0.050). In 48 cases (31.4%) in the intervention group, advice was given to improve empiric antibiotic treatment.

Conclusion: This type of program could help adjust antibiotic treatment when inappropriate, reducing antibiotic use and costs, length of stay, CDI and related mortality.

Keywords: Antimicrobial stewardship; GeneXpert® MRSA/SA SSTI; Microbiological techniques; Rapid diagnosis; Soft tissue infections.