Impact of the COVID-19 Pandemic on Health Care-Associated Infections and Antimicrobial Resistance in an ICU: A Comparative Three-Period Study

Healthcare-associated infections (HAIs) and antimicrobial resistance (AMR) are significant problems, especially in intensive care units (ICUs). We evaluated HAI rates, causative pathogens, resistance profiles, and antibiotic consumption retrospectively in a tertiary ICU across three 2-year periods—pre-pandemic period (PreP), pandemic period (PanP), and post-pandemic period (PostP)—to assess the impact of the COVID-19 pandemic. Antibiotic consumption was expressed as defined daily dose (DDD) per 1,000 patient days. The highest infection incidence rate and density were in PanP. Despite lower invasive device use, PanP had a higher rate of catheter-related bloodstream infections (BSIs). The most frequent pathogen across periods was Acinetobacter spp., although its rate declined in PostP. Gram-negative bacteria resistance rates to piperacillin-tazobactam, carbapenem, and aminoglycoside were highest in PanP. Resistant pathogen and resistant infection rates were lower in PostP, and resistant infections were less frequent in PostP than in PanP (OR: 0.371; 95% CI: 0.216–0.637; p < 0.001). Healthcare-associated pneumonia (HAP) was associated with a higher risk of resistance compared with BSI (OR: 3.467; 95% CI: 2.139–5.621; p < 0.001). Total antibiotic consumption remained comparable between PreP and PanP but increased in PostP. During the PanP, carbapenem use increased while piperacillin–tazobactam consumption decreased, whereas glycopeptide use increased and reached its highest level in PostP. Pandemic-related disruptions in the health care system may have contributed to increases in HAI and AMR rates, whereas improvements in the PostP may have supported recovery. Continuous surveillance, infection prevention measures, and antimicrobial stewardship programs are essential to mitigate the impact of future health care crises.