Healthcare-associated infections before and during the pandemic: four-year follow-up

Healthcare-associated infections (HAIs) are important because they increase morbidity and mortality, prolong hospital stays, raise healthcare costs, and reduce quality of life. Identifying HAIs and assessing pathogen distribution and antimicrobial resistance patterns are essential for effective infection prevention and control. The COVID-19 pandemic has posed additional challenges to hospital infection control. Therefore, this study aimed to compare the incidence and characteristics of HAIs before and during the pandemic. This retrospective study analyzed the surveillance records of HAIs and their causative agents in our hospital between January 2018 and December 2021. The incidence of HAIs, the distribution of causative microorganisms, and antimicrobial resistance profiles were compared between the pre-pandemic and pandemic periods. The overall rate and incidence density of HAIs were 0.97 and 2.08 in 2018–2019, and 0.91 and 2.04 in 2020–2021, respectively, with no statistically significant difference between the two periods. The most common HAIs identified across all years were bloodstream infections, followed by pneumonia and surgical site infections. A significant increase in the rate of pneumonia was observed during the pandemic period (p = 0.0011). Most of the pathogens isolated throughout the study period were Gram-negative bacteria, while the proportion of Gram-positive bacteria was significantly lower during the pandemic period (p = 0.004). Among all isolates, Acinetobacter spp., Klebsiella spp., and Pseudomonas spp. were the most frequently detected pathogens. During the pandemic period, the rate of Klebsiella spp. increased, whereas the rates of E. coli, coagulase-negative Staphylococcus, and Enterococcus spp. decreased. Over the years, antimicrobial resistance among Gram-negative bacteria showed an increasing trend, while a decline in vancomycin-resistant Enterococcus rates was observed. The most common device-associated infection in intensive care units was ventilator-associated pneumonia (VAP). The COVID-19 pandemic challenged infection control due to increased patient load and healthcare worker burden, leading to a rise in pneumonia and VAP cases. The decline in Gram-positive pathogens suggests limiting the empirical use of glycopeptides, while the increase in resistant Gram-negative bacteria underscores the need for strengthened, data-driven infection control and antimicrobial stewardship programs.