Comparison of Antibiotic Use and Bacterial Infections among Patients Hospitalized to the Intensive Care Unit During the First and Fifth Wave of COVID-19 Pandemic in a University Hospital in Iran

Abstract

Background: The overuse of antibiotics during the COVID-19 pandemic has increased the risk of antimicrobial resistance, posing a serious challenge to healthcare systems. This study aimed to compare patterns of antibiotic consumption and microbial resistance among ICU-admitted COVID-19 patients during two different waves of the pandemic. Methods: This descriptive cross-sectional study was conducted on COVID-19 patients admitted to the ICU during the first (2020) and fifth (2021) waves of the pandemic. Indicators such as mortality rate, number of microbial cultures, frequency of Gram-positive and Gram-negative bacteria, antibiotic consumption, and antibiotic resistance patterns in Gram-negative bacteria were evaluated. Findings: During the first wave, 439 patients and during the fifth wave, 506 patients were admitted to the ICU. Positive bacterial infections were reported in 12.3 and 15.8 of patients, respectively, while mortality rates were 35 and 40.9. Klebsiella pneumoniae was the most common organism in both waves, and the lowest resistance was observed to colistin. In the first wave, meropenem (3,316 vials) and vancomycin (1,937 vials) had the highest usage, whereas in the fifth wave, levofloxacin (1,745 vials) and meropenem (1,735 vials) were the most prescribed antibiotics. Conclusion: In the fifth wave, the implementation of infection control programs and antimicrobial stewardship led to a reduction in antibiotic consumption and decreased drug resistance among Gram-negative bacteria. These findings highlight the importance of continuing such interventions in the management of ICU patients. © 2025, Isfahan University of Medical Sciences(IUMS). All rights reserved.