Title: Characterization of Human-Generated Infectious Aerosol to Improve the Understanding of Disease Transmission and Building-Level Interventions
C.J. WOSLAGER, Vicki Herrera, Ashley R. Ravnholdt, Elizabeth A. Klug, Daniel N. Ackerman, Danielle N. Rivera, Joshua L. Santarpia, University of Nebraska Medical Center
Abstract Number: 47
Working Group: Bioaerosols
Abstract
Understanding the origins of infectious bioaerosols, within the human respiratory system, is critical to developing effective mitigations for respiratory transmission. Despite research into the sizes of aerosols produced by human respiration and characterizations of human-generated infectious aerosol in the environment, there remains significant uncertainty in the size of particles that present the greatest risk of transmission and, therefore, the most effective mitigation strategies. This study aims to estimate the origin and composition of human-generated respiratory aerosol in asymptomatic individuals and those with respiratory infections by looking at both viral and human respiratory protein content in size-resolved aerosol collections. In addition, we aim to determine the efficacy of building-level interventions (such as HVAC filtration) in removing these aerosols and thus limiting transmission. In this study, we invite subjects to participate in a two-hour aerosol collection session involving normal breathing and optional vocalizations. Concurrently, we collect shallow nasal swabs and saliva samples to compare them with environmental aerosols. To assess mitigation efficacy, we collect air samples through a modified door connected to an HVAC unit operating under three filtration conditions: no filter, MERV 8, and MERV 13. We analyze respiratory proteins (surfactant protein-D, surfactant protein-C, Proline-Rich Protein BstNI Subfamily 2, Aquaporin-5, Mucin-5AC, and Mucin-5B) and viral loads using qPCR to generate cycle threshold values. This work will advance the understanding of bioaerosol origin and composition, improve sampling strategies for future aerosol studies, and identify practical filtration approaches for reducing airborne transmission.