Background/Objectives: Carbapenem-resistant Acinetobacter baumannii (CRAB) is a priority nosocomial pathogen with limited therapeutic options and high attributable mortality, particularly in intensive care units (ICUs). Whether the pandemic-era rise in institutional CRAB burden resolved, persisted, or stabilized at a sustained high level remains incompletely characterized at the single-hospital level. Methods: We conducted a retrospective observational study of all non-duplicate clinical A. baumannii complex isolates recovered at a 450-bed regional teaching hospital in central Taiwan between January 2020 and December 2024. Isolates were classified as CRAB based on non-susceptibility (intermediate or resistant) to imipenem or meropenem. Annual and monthly isolation rates, ICU versus non-ICU distribution, and temporal trends were analyzed. Results: Among 582 A. baumannii complex isolates, 340 (58.4%) were classified as CRAB. The annual CRAB isolation rate differed significantly across the study period (p = 0.0099), rising sharply from 44.0% (51/116) in 2020 to 63.9% (76/119) in 2021 and subsequently remaining between 58.3% (60/103) and 63.2% (67/106) through 2024. Monthly isolation rates varied widely (16.7–100.0%) without a consistent seasonal pattern. The proportion of CRAB isolates originating from ICU settings varied year to year, rising from 45.1% (23/51) in 2020 to a peak of 67.4% (58/86) in 2022 and then declining to 49.3% (33/67) in 2024, without a statistically significant overall trend (p = 0.054). Conclusions: These findings suggest that CRAB isolation rates remained at a sustained elevated level after the acute pandemic phase and highlight ICUs as an important focus for institution-level infection prevention and antimicrobial stewardship efforts.
Chen et al. (Mon,) studied this question.