Assessing the Impact of COVID-19 on the Epidemiology of Acinetobacter baumannii: A Longitudinal Study Spanning from 2014 to 2023

Abstract Background Understanding the changes in the epidemiological characteristics of Acinetobacter baumannii before and after the COVID-19 pandemic may provide a scientific basis for clinical treatment and public health management. Methods Over a 10-year span from 2014 to 2023, a tertiary hospital in China separated A. baumannii isolated from patients according to whether it was carbapenem-resistant or carbapenem-sensitive. Information, such as sample type, drug sensitivities, MIC50, seasonal differences, and variances in patient sex, age, department, and outpatient and inpatient status, was examined. Results A total of 3,498 isolates of A. baumannii were assessed, including 1909 (54.6%) carbapenem-resistant A. baumannii (CRAB), 1501 (42.9%) carbapenem-sensitive A. baumannii (CSAB) isolates, and 88 (2.5%) carbapenem-intermediate A. baumannii isolates. Since the COVID-19 pandemic outbreak, the isolation rate of A. baumannii in outpatients had sharply decreased to 6.4%, while it had surged to 110% in inpatients. Simultaneously, the proportion of CRAB isolates had decreased to 67.3%, whereas that of CSAB isolates had increased to 150.8%. Notably, overall, the resistance rate of A. baumannii to 17 antibiotics decreased, with the most significant decreases in the combined sulfamethoxazole and amikacin, with decreases to 51.1% and 53.9%, respectively (p < 0.05). However there was an increase in the usage rate of moxifloxacin to 146.9%. The distribution proportion of CSAB in the third quarter was 0.6 times higher than that in the other three quarters, while the distribution of CRAB throughout the year was relatively balanced. Conclusions During the COVID-19 pandemic, significant changes occurred in people’s lifestyle. The notable decrease in the CRAB isolation rate highlights the effectiveness of strict isolation measures for controlling the transmission of drug-resistant bacteria in hospitals.