Implementation of mRSA nasal swabs to decrease anti-mrsa therapy in COVID-19 infection

ABSTRACT

INTRODUCTION: Limited information is available to guide antimicrobial stewardship interventions in COVID-19 infections. Two meta-analyses have been published to date showing a rate of bacterial co-infection between 7-8% in COVID-19, with only 1 case of methicillin-resistant Staphylococcus aureus (MRSA) among those publications. METHODS: In an effort to optimize use of anti-MRSA therapy, the COVID-19 Task Force at this large, hybrid community and academic medical center implemented routine MRSA nasal swabs for all COVID-19 patients, suspected or confirmed, requiring anti-MRSA therapy. This retrospective review was conducted to evaluate the use of MRSA nasal swabs in patients admitted between April 13, 2020 and July 26, 2020. Electronic health record-generated reports were created to identify patients with a diagnosis code of COVID-19 infection or COVID-19 rule out who also received an MRSA nasal swab. RESULTS: Out of 263 patients identified with MRSA nasal swabs, 113 patients were included in the final analysis. Almost 75% of patients required ICU admission and the overall mortality rate was 41.6%. A total of 12 swabs (10.6%) resulted as positive for MRSA. In response to swab results, 54 patients (47.8%) had anti-MRSA agents discontinued and another 37 patients (32.7%) were never started on anti-MRSA therapy (collectively referred to as ?discontinued? in this report). The median duration of anti-MRSA therapy overall was 12 hours (12 hours in the discontinued group versus 120 hours in the continued group). Sputum cultures were obtained in 29 patients, with pathogens identified in 13. Most pathogens were gram-negative, including Pseudomonas aeruginosa in 8 cases. Methicillin-resistant Staphylococcus aureus was isolated in sputum cultures of two patients;both had MRSA positive nasal swabs and were continued on anti- MRSA therapy. CONCLUSIONS: With implementation of MRSA nasal swabs in COVID-19 patients, anti-MRSA therapy was reduced in 80.5% of patients in the study cohort, with median duration 12 hours for anti-MRSA therapy. Of the 22 patients with therapy continued, 11 were for pneumonia and MRSA positive swab and 10 for treatment of an alternative indication. MRSA nasal swabs may serve as an effective antimicrobial stewardship tool in COVID-19 pneumonia.