Comparison of the Infection Characteristics and Antimicrobial Use Among Patients Hospitalized in the Intensive Care Unit During and After the COVID-19 Pandemic Periods

Abstract

Introduction: During the severe acute respiratory syndrome-Coronavirus-2 pandemic, intensive care units (ICUs) were pivotal in treating severe cases. In the ICU, invasive procedures and the use of immunosuppressive drugs have been associated with an increased risk of infection. We aimed to compare the antibiotic use, infection types, culture positivity, and resistance patterns among patients in the ICU during and after the pandemic Materials and Methods: The patients who were followed up in the adult ICU at our hospital were retrospectively assessed after being divided into two groups. Group 1 included patients admitted between December 1, 2020, and May 5, 2021, (pandemic group). Group 2 consisted of patients admitted between June 1, 2021, and November 1, 2023 (post-pandemic). Results: Antibacterial (100% vs. 92.7%, p=0.003), and antifungal (33.3% vs. 10.7%, p<0.001) use was significantly higher during the pandemic in comparison to the post-pandemic period. Additionally, multiple classes of antimicrobial drugs were used and antivirals were administered more commonly during the pandemic than after the pandemic (p<0.001). The interval from admission to antimicrobial therapy, duration of antimicrobial therapy, and total length of hospital stay were statistically longer during the pandemic than after the pandemic. The culture-positive endotracheal aspirates (ETAs) were more frequently observed during the pandemic than after it (56% vs. 42.1%, p=0.019). The proportion of patients in whom Klebsiella spp. were identified in the ETA was higher during the pandemic than after the pandemic (19.1% vs. 7.3%). Furthermore, the blood cultures yielded the growth of Stenotrophomonas maltophilia, Klebsiella spp., and Candida spp. more commonly in the pandemic group than in the postpandemic period. There was no statistically significant difference in the proportion of patients who developed methicillin-resistant Staphylococcus aureus infection (p=0.473), methicillin-resistant coagulase-negative Staphylococcus infection (p=0.263), or third-generation cephalosporinresistant (p=0.658) and carbapenem-resistant Gram-negative infections (p=0.214) between the two time periods. Conclusion: In our study, a notable disparity was observed in the antibiotic usage rates and types between the two study groups. We hypothesize that this discrepancy may be attributed to the rigorous implementation of infection control measures and the enhanced effectiveness of the antibiotic stewardship committee, particularly during and following the period of reduced epidemic burden.