Outbreak of Pseudomonas Aeruginosa Producing VIM Carbapenemase in an Intensive Care Unit and its termination by implementation of waterless patient care

Abstract

Background: Long-term outbreaks of multidrug-resistant Gram-negative bacilli related to hospital-building water systems have been described. However, successful mitigation strategies have rarely been reported. In particular, environmental disinfection or replacement of contaminated equipment usually failed to eradicate environmental sources of Pseudomonas aeruginosa.Methods: We report the investigation and termination of an outbreak of P. aeruginosa producing VIM carbapenemase (PA-VIM) in the adult intensive care unit (ICU) of a Swiss tertiary care hospital with active case finding, environmental sampling and whole genome sequencing (WGS) of patient and environmental strains. We also describe the implemented control strategies and their effectiveness on eradication of the environmental reservoir.Results: Between April 2018 and September 2020, 21 patients became either infected or colonized with a PA-VIM strain. For 16 of them, an acquisition in the ICU was suspected. Among 131 environmental samples collected in the ICU, 13 grew PA-VIM in sink traps and drains. WGS confirmed the epidemiological link between clinical and environmental strains and the monoclonal pattern of the outbreak. After removing sinks from patient rooms and implementation of waterless patient care, no new acquisition was detected in the ICU within 6 months after the intervention.Discussion: Implementation of waterless patient care with removal of the sinks in patient rooms was successful for termination of a PA-VIM ICU outbreak linked to multiple environmental water sources. WGS provides highly discriminatory accuracy to investigate environment-related outbreaks.

Molecular Characterization of Carbapenem-Resistant Acinetobacter baumannii Isolates Among Intensive Care Unit Patients and Environment

“…Recent researcher has revealed the environmental contamination of CRAB was existed and had an epidemiological link between clinical samples. 13 , 14 These results suggest that the environment could be a route of cross-transmission, which eventually causes HAIs among patients to be possible.…”

Role of the environment in transmission of Gram-negative bacteria in two consecutive outbreaks in a haematology-oncology department

“…For transmission prevention of highly resistant opportunistic plumbing premise pathogens, design and construction of the water system of newly built hospitals is critical [ 17 ]. Also the implementation of waterless patient care is an expensive, but effective method to discontinue hospital transmission [ 18 ].…”

Genome-based typing reveals rare events of patient contamination with Pseudomonas aeruginosa from other patients and sink traps in a medical intensive care unit

“…In addition, investigations of hospital outbreaks have identi ed the water supply system as the source of the PA outbreaks (19). This has led to infection control departments to recommend sink trap disinfection or sink removal or redesign in high-risk wards, such as ICUs and hematology units (20,21).…”