Utility of Three Nebulizers in Investigating the Infectivity of Airborne Viruses

Laboratory-generated bioaerosols are widely used in aerobiology studies of viruses; however, few comparisons of alternative nebulizers exist. We compared aerosol production and virus survival for a Collison nebulizer, vibrating mesh nebulizer (VMN), and hydraulic spray atomizer (HSA). We also measured the dry size distribution of the aerosols produced and calculated the droplet sizes before evaporation and the dry size distribution from normal saline solution. Dry count median diameters of 0.11, 0.22, and 030 mu m were found for normal saline from the Collison nebulizer, VMN, and HSA, respectively. The volume median diameters were 0.323, 1.70, and 1.30 mu m, respectively. The effect of nebulization on the viability of two influenza A viruses (IAVs) (H1N1 and H3N2) and human rhinovirus 16 (HRV-16) was assessed by nebulization into an SKC BioSampler. The HSA had the least impact on surviving fractions (SFs) of H1N1 and H3N2 (89% +/- 3% and 94% +/- 2%, respectively), followed by the Collison nebulizer (83% +/- 1% and 82% +/- 2%, respectively). The VMN yielded SFs of 78% +/- 2% and 76% +/- 2%, respectively. Conversely, for HRV-16, the VMN produced higher SFs (87% +/- 8%). Our findings indicate that there were no statistical differences between SFs of the viruses nebulized by these nebulizers. However, VMN produced higher aerosol concentrations within the airborne size range, making it more suitable where high aerosol mass production is required. IMPORTANCE Viral respiratory tract infections cause millions of lost days of work and physician visits globally, accounting for significant morbidity and mortality. Respiratory droplets and droplet nuclei from infected hosts are the potential carriers of such viruses within indoor environments. Laboratory-generated bioaerosols are applied in understanding the transmission and infection of viruses, modeling the physiological aspects of bioaerosol generation in a controlled environment. However, little comparative characterization exists for nebulizers used in infectious disease aerobiology, including Collison nebulizer, vibrating mesh nebulizer, and hydraulic spray atomizer. This study characterized the physical features of aerosols generated by laboratory nebulizers and their performance in producing aerosols at a size relevant to airborne transmission used in infectious disease aerobiology. We also determined the impact of nebulization mechanisms of these nebulizers on the viability of human respiratory viruses, including IAV H1N1, IAV H3N2, and HRV-16.

Automated summary

Laboratory-generated bioaerosols are widely used in studying virus transmission. In this study, we compared the performance of different nebulizers in aerosol production and virus survival. The results showed that while the hydraulic spray atomizer had the least impact on influenza viruses, the vibrating mesh nebulizer had the least impact on human rhinovirus.