Ward microclimate and procedural factors as predictors for CRAB environmental contamination in ICUs: a longitudinal monitoring study

BACKGROUND: Carbapenem-resistant Acinetobacter baumannii (CRAB) has emerged as a pivotal pathogen contributing to healthcare-associated infections. Identifying environmental risk factors associated with CRAB contamination is critical. OBJECTIVES: To assess the associations of ward microclimate and procedure duration with CRAB contamination risks. METHODS: High-touch environment and exposure surface, and air samples were repeatedly measured. A total of 2330 high-touch environment surfaces, 345 exposure surfaces, and 366 air samples were collected. The generalized linear mixed-effects model and additive interaction analysis were employed to examine the associations of ward microclimate and procedural factors with environmental CRAB contamination risks. RESULTS: We found that compared to procedures lasting ≤15min, those lasting >15min were related to higher risks of CRAB contamination (OR: 1.435, 95% CI: 1.052, 1.954). Compared to the standard environmental conditions (22.5-25.5 °C for temperature and 30-60% for humidity), lower temperature (60%) and CRAB contamination risks. The combination of lower temperature or humidity with prolonged procedures showed synergistical interaction on increased risks of CRAB contamination. Additionally, CRAB was consistently detected in air across all sampling scenarios (static conditions, real-time nursing care procedures, and real-time sanitation), with the nursing care procedures group showing the highest detection rate (29.66% vs. 13.95% for static conditions and 8.33% for real-time sanitation). CONCLUSIONS: Temperature and humidity below standard thresholds, combined with prolonged procedures were associated with an increased risk of environmental CRAB contamination in ICUs.