10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Conducting Inhalation Exposures Using Bioaerosols; Infectious Microorganisms and Toxins: Concepts and Lessons Learned
ROY BARNEWALL, Battelle, Columbus Ohio
Abstract Number: 254 Working Group: Infectious Bioaerosol
Abstract Medical countermeasures such as vaccines and pharmaceuticals that are used to protect against or treat diseases caused by biological agents (bacteria, viruses and toxins), are often evaluated for efficacy against these agents via inhalation, which is a probable route of exposure from a natural infection, accidental release or deliberate release. Testing of animal models of infection or disease need to be conducted safely by using well characterized biological material and well characterized inhalation systems with highly controlled procedures and processes in order to ensure reproducibility and consistency in the inhaled or presented dose of the microorganism or toxins. This is especially true for research which will be used in support of product licensure by the U.S. Food and Drug Administration.
This presentation will briefly outline the universal components of an inhalation exposure system and a few of the various types of exposure systems available and what is used by Battelle. Additionally, the practical and safety aspects of performing inhalation dosing using these agents will be discussed. The primary focus of the presentation will be on the concepts of performing bioaerosol exposures and physical properties of the environment that can affect the agent and the agents themselves and how they may impact the bioaerosol. The presentation will conclude with lessons learned over the years of performing bioaerosol testing. The effects of agent preparation, sampler choice, temperature and relative humidity, volume within the sampler, and agent strain differences on how they may affect the characterization of an aerosol system were evaluated. Some examples that will be discussed are that testing revealed that the optimal sampler chosen for dose quantification is primarily dictated by the biological agent being tested. For many bacterial aerosols an impinger was the most practical while gelatin filters were optimal for some viruses. The choice of media used and how the agent is prepared will have an effect on viability as will the temperature and humidity levels. The effect of temperature and humidity varied based on the agent with high temperature and humidity (70% and higher) predominately resulting in lower viability or infectivity compared to higher viability or infectivity at lower relative humidity (approximately 50%). Once these different factors are optimized and controlled, will minimize intra-day and inter-day variability and allow for the reproducible dose results within a study and between studies.