Abstract Number: 57 Working Group: Health Related Aerosols
Abstract Several viruses can be transmitted by the airborne route. However, few is known about their aerosolization, propagation, and survival in aerosol state. Moreover, information about sampling effect on viruses is limited. The aim of this study was 1) to evaluate the effect of aerosolization and relative humidity in airborne state as well as 2) effects of air sampling on Influenza virus integrity.
We utilized a live attenuated Influenza vaccine as viral strain. We spiked 2 liquid cyclone air samplers (SKC Biosampler and Coriolis µ) and let them run with clean HEPA filtered air in order to assess damages caused to the viruses into the air samplers. Our results demonstrated that 5% of influenza virus remains infectious into the Coriolis µ after 10 min air sampling at 300 L/min and 2.5% in the Biosmpler after 20 min air sampling. Moreover, 4% of the virus remains infectious after nebulisation with the Collison 6-jet into a 50L rotating chamber and sampling using the Biosampler. The effect of relative humidity on airborne Influenza viruses was also evaluated. Influenza viruses were arosolized into a 50L rotating environmental chamber under 20% and 80% RH. Aerosols were kept in suspension for 0h, 6h and 14h at 18°C. At 20% RH, Influenza viruses infectivity decreased of 90% in the first 6 hours and remains stable between 6h and 14h. The infectivity loss was higher under 80% RH. Indeed, Influenza viruses lose 99.6% infectivity within the first 6 hours exposure compare to the aerosols at time 0h.
Based on these results, nebulisation with the Collison 6-jet does not seem to affect the infectivity of Influenza viruses. However, air sampling causes substantial infectivity loss. Once airborne, Influenza viruses can remain infectious even after 14h. We also demonstrated that airborne Influenza viruses remain more infectious at 20% RH when compared to 80% RH.