Background:  During the Coronavirus Disease 2019 (COVID-19) epidemic, the strain on intensive care units (ICUs) has increased, which made them more vulnerable to the threat of multidrug-resistant organism (MDRO).

Aim: This study aims to investigate an outbreak of carbapenem resistant Acinetobacter baumannii (CRAB) infection in an ICU of a tertiary hospital in China during the COVID-19 epidemic and evaluate the effectiveness of intervention measures.

Methods: Demographic and clinical data of patients were collected, and suspected contaminated environments were sampled. Whole genome sequencing (WGS) analysis was performed on clinical and environmental isolates. An evolutionary tree was constructed based on the WGS data. The infection control team implemented a bundle of MDRO interventions, including a termination of COVID-19 infection control measures and implementation of ‘three-step’ cleaning and disinfection method.

Findings: Thirty-seven patients were detected with CRAB in the ICU from December 2022 to April 2023. Twelve CRAB isolates were obtained from the environment and medical equipment. The evolutionary tree suggested a possible link between the outbreak and contaminated environments, particularly due to inadequate disinfection of bronchoscopes. Following intervention, the CRAB detection rate gradually declined, with no positive samples for CRAB found in the ICU environment or on bronchoscopes.

Conclusion: The infection control measures for COVID-19 conflicted with basic MDRO prevention and control strategies, likely contributing to the outbreak. Therefore, established infection prevention and control measures should be consistently followed, as they represent the most effective approach to preventing MDRO.

Yi Kong has completed her master of medical microbiology at the age of 25 years from RMIT. She is an associate researcher at the Infection Control Department of Nanjing Drum Tower Hospital, a large tertiary university teaching hospital. She has published more than 20 papers in reputed journals and has been serving  a member of the Jiangsu Research Hospital Association in China.