Impact of COVID-19 isolation measures on ICU microbial resistance dynamics: simulation-based statistical modeling...

Area of Science:

• Infectious Diseases
• Critical Care Medicine
• Microbiology

Background:

• Antibiotic-resistant bacteria (ARB) in intensive care units (ICUs) present a major infection control challenge.
• Distinguishing between endogenous acquisition and cross-transmission of ARB is crucial for effective strategies.
• The COVID-19 pandemic offered a unique opportunity to study ARB transmission dynamics due to altered hygiene protocols.

Purpose of the Study:

• To investigate the primary drivers of resistant bacterial acquisition in ICUs.
• To differentiate the contributions of endogenous selection versus exogenous cross-transmission.
• To assess the impact of varying hygiene protocols on ARB prevalence and transmission.

Main Methods:

• Retrospective analysis of microbiological data from two ICUs (2018-2021).
• Application of machine learning and random simulation models to analyze bacterial clustering and transmission patterns.
• Comparison of bacterial findings across pre-COVID, COVID, and inter-COVID periods with distinct hygiene measures.

Main Results:

• Prevalence of Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and resistant Klebsiella pneumoniae/Escherichia coli significantly increased during the COVID period.
• A higher proportion of bacterial detections occurred after 48 hours of ICU admission during COVID.
• Clustering analysis indicated limited cross-transmission, except for Pseudomonas aeruginosa and potential environmental persistence of Stenotrophomonas maltophilia.

Conclusions:

• Antibiotic selection pressure is the main factor in resistant bacteria acquisition within ICUs.
• Direct cross-transmission plays a minor role in the spread of most resistant bacteria.
• Environmental persistence of certain bacteria necessitates improved decontamination protocols in ICUs.