Risk factors for transmission of carbapenem-resistant Acinetobacter baumannii in outbreak situations: results of a
Beate Schlosser1, Beate Weikert2, Giovanni-Battista Fucini2
1Institute of Hygiene and Environmental Medicine, Charité- Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt- Universität zu Berlin, Hindenburgdamm 27, 12203, Berlin, Germany. beate.schlosser@charite.de.
Background:
An increase in patients with multidrug-resistant organisms and associated outbreaks during the COVID-19 pandemic have been reported in various settings, including low-endemic settings. Here, we report three distinct carbapenem-resistant Acinetobacter baumannii (CRAB) outbreaks in five intensive care units of a university hospital in Berlin, Germany during the COVID-19 pandemic.
Methods:
A case-control study was conducted with the objective of identifying risk factors for CRAB acquisition in outbreak situations. Data utilized for the case-control study came from the investigation of three separate CRAB outbreaks during the COVID-19 pandemic (August 2020- March 2021). Cases were defined as outbreak patients with hospital-acquired CRAB. Controls did not have any CRAB positive microbiological findings and were hospitalized at the same ward and for a similar duration as the respective case. Control patients were matched retrospectively in a 2:1 ratio. Parameters routinely collected in the context of outbreak management and data obtained retrospectively specifically for the case-control study were included in the analysis. To analyze risk factors for CRAB acquisition, univariable and multivariable analyses to calculate odds ratios (OR) and 95% confidence intervals (CI) were performed using a conditional logistic regression model.
Results:
The outbreaks contained 26 cases with hospital-acquired CRAB in five different intensive care units. Two exposures were identified to be independent risk factors for nosocomial CRAB acquisition by the multivariable regression analysis: Sharing a patient room with a CRAB patient before availability of the microbiological result was associated with a more than tenfold increase in the risk of nosocomial CRAB acquisition (OR: 10.7, CI: 2.3-50.9), while undergoing bronchoscopy increased the risk more than six times (OR: 6.9, CI: 1.3-38.1).
Conclusions:
The risk factors identified, sharing a patient room with a CRAB patient and undergoing bronchoscopy, could point to an underperformance of basic infection control measure, particularly hand hygiene compliance and handling of medical devices. Both findings reinforce the need for continued promotion of infection control measures. Given that the outbreaks occurred in the first year of the COVID-19 pandemic, our study serves as a reminder that a heightened focus on airborne precautions should not lead to a neglect of other transmission-based precautions.
Insights
During the COVID-19 pandemic, sharing rooms with patients who have carbapenem-resistant Acinetobacter baumannii (CRAB) and undergoing bronchoscopy significantly increased the risk of CRAB acquisition in intensive care units. These findings highlight the need for strict adherence to infection control measures.
Area of Science:
- Infectious Diseases
- Critical Care Medicine
- Epidemiology
Background:
- The COVID-19 pandemic has seen an increase in multidrug-resistant organisms, including carbapenem-resistant Acinetobacter baumannii (CRAB).
- Three distinct CRAB outbreaks occurred in intensive care units (ICUs) of a university hospital in Berlin during the COVID-19 pandemic.
Purpose of the Study:
- To identify risk factors for CRAB acquisition during outbreak situations in an ICU setting.
- To evaluate the impact of patient room sharing and medical procedures on CRAB transmission.
Main Methods:
- A case-control study was conducted involving 26 CRAB cases and matched controls.
- Data were collected retrospectively from outbreak investigations and specifically for the study.
- Conditional logistic regression analysis was used to determine independent risk factors for CRAB acquisition.
Main Results:
- Sharing a patient room with a CRAB-positive patient before diagnosis increased acquisition risk over tenfold (OR: 10.7).
- Undergoing bronchoscopy increased the risk of CRAB acquisition more than sixfold (OR: 6.9).
- These factors suggest potential underperformance in basic infection control measures.
Conclusions:
- Sharing patient rooms and bronchoscopy are significant risk factors for CRAB acquisition in ICUs.
- Reinforces the critical importance of hand hygiene and proper handling of medical devices.
- Highlights the need to maintain all transmission-based precautions, not just airborne, during pandemics.
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