The modes of person-to-person transmission of influenza viruses, especially with regard to the airborne transmission via inhalation of fine (<5 microns) particles, are highly debated. A team comprised of researchers from the Department of Environmental and Global Health, the UF School of Medicine, the UF Department of Environmental Engineering Sciences, the UF Department of Environmental Health and Safety, and the Veterans Health Administration’s National Center for Occupational Health and Infection Control, with some of the researches affiliated with the UF Emerging Pathogens Institute, are developing methods to study the role of fine particle aerosols in the spread of seasonal influenza. In this project, the team first designed and assembled an aerosol-generating and -measuring system to safely generate size-characterized aerosols of viable influenza virus, then evaluated the use of a six-stage Andersen cascade impactor (ACI) for the collection of influenza virus aerosols. One of their innovations was to use liquid instead of semi-solid collection media in the ACI. Experimental results showed that the aerosol-generating system safely and consistently produced fine aerosols with a count median aerodynamic diameter (CMAD) of 0.87 µm. Recovery of viable virus was effective and facile when aerosols were collected in liquid media in Petri dishes in an ACI, then inoculated onto cell cultures.
Their open access article [Fennelly KP, Tribby MD, Wu CY, Heil GL, Radonovich LJ, Loeb JC, Lednicky JA. Collection and measurement of aerosols of viable influenza virus in liquid media in an Andersen cascade impactor. Virus Adaptation and Treatment 2015, 7:1-9] is freely available on the web: