Trends in Healthcare-Acquired Infections Due to Multidrug-Resistant Organisms at a German University Medical Center Before and During the COVID-19 Pandemic

Background: Healthcare-acquired infections due to multidrug-resistant organisms (MDR-HAIs) pose globally significant challenges to healthcare systems, leading to increased morbidity, mortality, and healthcare costs. According to the World Health Organization, the COVID-19 pandemic significantly impacted the burden of MDR-HAIs. The aim of this study was to investigate the dynamics and epidemiology of MDR-HAIs in inpatients at the University of Leipzig Medical Center (ULMC) before and during the COVID-19 pandemic. Methods: We compared data from inpatients with bacterial infections from 2017 to 2019 (pre-COVID-19) and from 2021to 2023 (during COVID-19) in a cross-sectional, monocentric, retrospective survey. This study focused on selected multidrug-resistant organisms (MDROs) and four clinical specimens. We analyzed the risk factors for MDR-HAIs using logistic regression models. Results: Out of 342,705 inpatients, 32,206 were diagnosed with a bacterial infection. The prevalence increased significantly from 8.09% (pre-COVID-19) to 10.79% (during COVID-19) (p < 0.001), but the proportion of MDROs decreased from 10.14% to 8.07%. The proportions of MDR-HAIs were 59.86% and 56.67%, respectively. The proportion of carbapenem-resistant Klebsiella pneumoniae and Enterobacter cloacae increased significantly. The risk of MDR-HAIs during COVID-19 decreased by 18% compared to pre-COVID-19 (p = 0.047). Longer hospital stays increased the risk of MDR-HAIs in both periods. This risk significantly decreased for children and the elderly during COVID-19. Conclusion: These findings show that it is also important to analyze epidemiological data at the facility level in order to evaluate the effectiveness of infection control practices even during unprecedented health crises like the COVID-19 pandemic.