Abstract
BACKGROUND: The COVID-19 pandemic has profoundly affected healthcare systems worldwide. High and often inappropriate antimicrobial use has been reported in COVID-19 care, potentially increasing the risk of bacterial resistance and other adverse events. This study aimed to characterize and quantitatively assess antimicrobial use among Brazilian patients hospitalized with severe acute respiratory syndrome (SARS) due to SARS-CoV-2 infection. METHODS: This retrospective observational cohort study included patients hospitalized with SARS caused by SARS-CoV-2 at the University Hospital of Brasília (HUB) during 2020 and 2021. Data on antimicrobial regimens, duration of therapy, and days of use were extracted from medical records. RESULTS: The median age was 61 years (IQR, 49-72); most patients were unvaccinated against COVID-19 (76.3%), and comorbidities were highly prevalent (90.1%). Patients were stratified by clinical severity at hospital discharge: 301 (47.2%) were classified as Severe COVID-19 and 337 (52.8%) as Critical COVID-19. Greater clinical severity was consistently associated with increased antimicrobial exposure across multiple indicators, including the proportion of patients receiving antimicrobials, days of therapy (DOT), length of therapy (LOT), and the DOT/LOT ratio and an inverse association was observed for antimicrobial-free days (AFD). According to the World Health Organization (WHO) AWaRe classification, Watch-group antibiotics were most frequently prescribed (91.9% of patients); however, Reserve-group antibiotics showed the greatest increases in both frequency and duration of use with increasing disease severity. CONCLUSIONS: In this single-center Brazilian cohort, antimicrobial therapy was highly prevalent (94.4%). Higher clinical severity was strongly associated with greater antimicrobial exposure and fewer AFD.