AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
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The Dissemination and Fate of Inert Aerosolized Particles in a Clinical Biocontainment Unit (BCU)
David Drewry, Thomas Pilholski, Jennifer Therkorn, FELIX SAGE, Kaitlin Rainwater-Lovett, Kathryn Shaw-Saliba, Lauren Sauer, Gregory Bova, Brian Garibaldi, Johns Hopkins University Applied Physics Laboratory
Abstract Number: 729 Working Group: Health Related Aerosols
Abstract Johns Hopkins Hospital created a Biocontainment Unit (BCU) to care for patients with highly infectious diseases (HIDs), such as influenza A (H7N9), while assuring healthcare worker (HCWs) safety. Research to date for BCU protocols and practices are based off of case reports and lessons learned from patient care and exercises. This study seeks to be the first to systematically study the influences of HCW movement and personal protective equipment (PPE) doffing, and the HVAC controls for containment. First, 1 µm fluorescent polystyrene beads (PSLs) were released by a biomimetic coughing device in the patient room. Then, the transport of the PSLs was examined under three BCU scenarios: 1) patient-only, no HCW; 2) HCW walk-through of the patient room; 3) 5-min HCW patient care activity. Airborne PSL concentrations were quantified every 1-second for 30 min throughout these scenarios by seven optical sensors (IBACs, FLIR Systems) located throughout the different areas within the BCU. Each BCU scenario was repeated at least 3 times. PSLs were undetected in the donning room area. In the patient room, the addition of a HCW walkthrough of the space and contamination of this HCW with PSLs prior to exiting increased the presence of PSLs near the exit door by a factor of 2.5 and 4.7, respectively. HCW removal of PPE and HCW movement throughout the space was found to re-aerosolize PSLs from their PPE and the floor, respectively. Next, we sought to test multiple HVAC failure conditions to understand the transport of PSLs within the BCU under abnormal operating conditions. Under failure conditions, we identified transport of PSLs from the patient room to the doffing room. This study provides a systematic method for evaluating airborne infection mitigation protocols in the BCU and suggests further steps to avoid HCW exposure to high risk pathogens in the BCU.