AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Highly Efficient Collection of Viable Influenza Virus A/Mexico/4108/2009 (pdmH1N1)
John Lednicky, MAOHUA PAN, Julia Loeb, Hsin Hsieh, Arantzazu Eiguren-Fernandez, Nima Afshar-Mohajer, Susanne Hering, Chang-Yu Wu, Hugh Fan, University of Florida
Abstract Number: 719 Working Group: Bioaerosols
Abstract Influenza infections pose significant public health threat, yet the measurement of airborne viable virus concentrations is difficult. Reported here is a new, efficient method for the viable capture of airborne influenza virus, referred to as “SESI”. Using a laminar flow, water-condensational growth, airborne particles as small as 10 nm are enlarged to form micrometer droplets that are gently deposited into liquid via low-velocity impaction. The condensational growth occurs in a straight, wide-bore, wet walled tubes with two temperature regions, ~8° and 40°C. Air is sampled at 7 L/min, with collection into 1.5 mL of water.
In controlled laboratory experiments, we evaluated the viable capture of H1N1 influenza virus by the SESI system, with comparison to a BioSampler impinger that collects into ~14 mL of liquid, and comparison to airborne virus concentrations calculated from experimental parameters. Pathogenic Influenza Virus A/Mexico/4108/2009 (pdmH1N1). (80-120 nm) was aerosolized using a Bioaerosol Nebulizing Generator and sampled using the SESI and a BioSampler, both of which operated at the same air flow rate. The concentration of viable virus in each sample was measured using Madin Darby canine kidney (MDCK) cells and a standard median tissue culture infectious dose (TCID50) assay to provide the virus titer (#/mL) of H1N1. This value was multiplied by the liquid sample volume to give the total number of viable viruses collected.
For collection times ranging from 5 min to 15 min, the viable H1N1 captured by the SESI was 9 times higher than for the BioSampler, with inferred airborne concentrations of 4200±380 viruses/L of air as compared with 470±160/L for the BioSampler. The SESI measurement of the airborne viable H1N1 concentration is 85% of that calculated from the virus concentration and consumed volume of the nebulizer solution, and the air volume into which it was diluted. As there could be generation losses as well, this indicates that the SESI efficiency for viable H1N1 capture was at least 85%.