Modeling environmental contamination in hospital single- and four-bed rooms

Area of Science:

• Environmental microbiology
• Infection control
• Healthcare engineering

Background:

• Aerial dispersion of pathogens is a known route for hospital-acquired infections.
• The interplay between healthcare worker (HCW) contact with surfaces, infection transmission, and hospital room design requires further investigation.

Purpose of the Study:

• To quantitatively model pathogen accretion on HCW hands during patient care.
• To assess the influence of hospital room design and care procedures on indirect infection transmission risk.

Main Methods:

• Combined computational fluid dynamics (CFD) simulations of bioaerosol deposition with a validated HCW-surface contact model.
• Estimated pathogen quantity on hands during six care procedures in single and four-bed rooms.
• Analyzed the impact of ventilation rates and patient location on pathogen loading.

Main Results:

• Care type and number of surface contacts were the most significant factors influencing hand contamination.
• Highest hand contamination occurred during personal care, despite high hand hygiene levels.
• Single rooms reduced pathogen accretion due to physical barriers, while four-bed rooms increased it due to pathogen spread.
• Ventilation rates had a minor impact, but patient positioning in multi-bed rooms was crucial.

Conclusions:

• The developed model quantitatively predicts pathogen transfer from surfaces to HCW hands.
• Single rooms significantly decrease cross-contamination risk from indirect transmission.
• Specific care activities and HCW housekeeping contribute to pathogen transmission.
• Hospital room design, ventilation, and patient placement are key modifiable factors to mitigate infection risk.