AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
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Comparison of the Performance of Pneumatic Atomizers for Inhalation Studies with Ebola Virus
KATIE BECK, Rebecca Dunning, Michael Schuit, Amy Reese, Jill Taylor, John Yeager, Paul Dabisch, BNBI / DHS NBACC
Abstract Number: 766 Working Group: Bioaerosols
Abstract The majority of studies assessing the inhalational virulence of Ebola virus have utilized the Collison nebulizer for aerosol generation. While the Collison nebulizer produces respirable aerosols with a mass median aerodynamic diameter in the 1-3 µm range, it also captures and recycles the majority of the output back into the reservoir, resulting in multiple passes of the suspension in the reservoir through the nozzle over the course of an exposure. Other studies have demonstrated that this recirculation can damage the microorganisms present, potentially altering the virulence upon subsequent inhalation. The aim of the present study was to compare the performance of the Collison nebulizer with that of a single-pass air assist nozzle with Ebola virus, and determine whether the single pass nozzle is comparable to the Collison nebulizer. The results demonstrate that the Collison nebulizer and the air assist nozzle produce similar initial particle size distributions when assessed using a phase Doppler particle analyzer. Additionally, the final particle distributions of aerosolized virus, measured using an Aerodynamic Particle Sizer sampling from the breathing zone of an inhalation exposure system, were similar for both generators, with MMADs < 2 µm, and GSDs < 2. Both atomizers also produced similar infectious aerosol concentrations in the inhalation exposure system. The Collison nebulizer did not appear to damage the virus present in the reservoir, as the infectious aerosol concentration measured in serial samples from the inhalation exposure system did not decrease over the 15-minute test. Taken together, these data demonstrate similar performance between the two pneumatic atomizers, and suggest that the single-pass air assist nozzle may be used as an alternative to the Collison nebulizer for inhalation studies with Ebola virus.