Pandemic stewardship on antimicrobials: A historical control study before and after COVID-19 care in a teaching hospital

Abstract Background: To see how the COVID-19 pandemic influenced the 3-year use of parenteral antimicrobials, we attempted a historical control study. Main body: Materials were the electronic medical record on the use of a total of 33 antimicrobials. We compared antimicrobial use density (AUD) of pre-pandemic 1 year (PreY), the first pandemic year (Pan1Y), and the second pandemic year (Pan2Y). Our antimicrobial team monitored all in-patients and COVID-19 patients underwent clinical pathways with antivirals. Results: showed that in a total of 20,013 patients (7,534, 6,146, and 6,333 for PreY, Pan1Y, and Pan2Y), sepsis-3 was diagnosed in 152, 132, and 283 patients while Clostridioides difficile toxin tests were positive in 17, 5, and 7 patients, respectively. Among patients with COVID-19 (N=622) at a median age of 58 (range, 1-99), 11 (1.8%) died; parenteral antimicrobials were given in 59 patients (9.5%) preceded by bacteriological tests in 48 (81.4%). Comparing before and during the pandemic, parametric analyses showed that the means of total AUD decreased from 16.767 (PreY) to 15.62 (Pan1Y+Pan2Y) (P=0.034). Likewise, the means of carbapenems’ AUD showed decrease from 0.773 (PreY) to 0.462 (Pan1Y) but increase into 0.777 (Pan2Y) (P=0.001).The non-parametric comparison between COVID-19 and other wards showed that the medians of AUD in the COVID-19 wards were significantly (P<0.05) less in 22 out of 33 antimicrobials (66.7%) and in the total AUD. Conclusion: The COVID-19 pandemic stewardship decreased the total AUD and may have contributed to decrease ESBL-producing microbes and C. difficile infection. The burden of sepsis-3 may have fluctuated the carbapenems’ use.