A Novel Approach for Short-Range Sampling of Respiratory Aerosols in Child Care Centers
ZHENYU MA, Peter Arts, Khalil Chedid, Aaron Prussin II, Andrew Hashikawa, Krista Wigginton, Adam Lauring, Linsey Marr, Emily Martin, Herek L. Clack,
University of Michigan Abstract Number: 760
Working Group: Aerosol Science of Infectious Diseases: Lessons and Open Questions on Models, Transmission and Mitigation
AbstractMITIGATE FLU is a multi-site project that seeks to enhance our understanding of influenza transmission by integrating laboratory, animal, and human studies. The human study arm of the project focuses on preschool children to study the correlation between incidence of influenza infection and influenza virus concentrations in child care center environments (surfaces and air) in Michigan. To investigate short-range influenza virus exposure and transmission and to circumvent the challenges of implementing direct breath collection with small children, we have developed an innovative approach for detecting viral aerosols in exhaled breath. A 4" diameter induced draft (ID) fan located in an insulated case at a distance from the children is connected by a flexible hose to an intake vent located behind Moxie, an AI robot toy from Embodied (https://moxierobot.com/) that engages the children in conversation. The ID fan draft induces airflow around the robot sufficient to entrain exhaled respiratory aerosols. Gelatin filters mounted around the internal periphery of the fan housing served to collect a portion of the entrained respiratory aerosols. After sampling, the filters are then dissolved in an aqueous buffer for further analyses.
The method was validated by ultrasonically nebulizing bacteriophage MS2 at a distance of 5 inches in front of the robot, approximating a child’s position. After nebulizing 10 mL of MS2 in solution for 15 min, viable MS2 viruses were successfully retrieved from the gelatin filter, with an overall recovery rate of about 0.01‰. RT-ddPCR analysis for collected gene copies reveals a recovery rate of 0.03‰, higher than the recovery rate for viable phages due to phage inactivation after collection on the gelatine filters.
Our approach proposes a novel, less-intrusive method for short-range sampling of respiratory aerosols to identify the potential for airborne infectious virus exposure in child care center settings.