Comparison Of The Performance Of Aerosol Sampling Devices With Aerosols Containing Ebola Virus

Previous laboratory studies of Ebola virus aerosols have used a variety of different sampling devices to collect viral material for analysis. However, sampling devices vary in their ability to collect aerosol particles and preserve the infectivity of collected viruses. If not accounted for, this variability has the potential to bias study outcomes and confound comparisons between studies in which different samplers are used. In the present study, five laboratory-scale aerosol samplers were assessed for their ability to collect and preserve the infectivity of Ebola virus at low and high relative humidities. Relative humidity did not affect physical collection efficiencies, but infectivity was preserved better at high relative humidity for most samplers. Overall, 25-mm gelatin filters were identified as the optimal sampler among those tested based on their physical and biological efficiency, ease of use, lack of glass components, and ability to be recovered in small volumes to produce a more concentrated final sample. Tests demonstrated that 25-mm gelatin filters recovered in 2.5-mL media and assayed by microtitration using an Ebola reporter cell line resulted in an approximately 10-fold improvement in sensitivity compared to other published methods. The data provided by this study will be useful to facilitate comparisons between different studies utilizing aerosolized Ebola virus and to inform sampler selection in future studies.