Improving Protection against Viral Aerosols Through Development of Novel Decontamination Methods and Characterization of Viral Aerosol.

摘要

Although respirators and filters are designed to prevent the spread of pathogenic aerosols, a stockpile shortage is anticipated during the next flu pandemic. Contact transfer and reaerosolization are also concerns. An option to address these potential problems is to decontaminate used respirators/filters for reuse. In this research a droplet/aerosol loading chamber was built and used in decontamination testing to proved a fair comparison of the performance of different decontamination techniques, including antimicrobial chemical agents, microwave irradiation and ultraviolet (UV) irradiation, which were incorporated into filtration systems and tested. The inactivation efficacy of dialdehyde cellulose and starch filters s biocidal filters was investigated. In sufficiently humid conditions both media showed higher removal efficiency and better disinfection capability at lower pressure drop than conventional media. In microwave-assisted filtration systems temperature (T) was found to be a key factor. Relative humidity (RH) was another pivotal parameter at warm-to-hot- water temperatures but became insignificant above 90 C. An examination of the effect of T and RH on UV inactivation revealed that absorption of UV by water and shielding of viruses inside aggregates suppressed inactivation. Varying the spray medium showed that artificial saliva (AS) and beef serum extract (BE) produce a protective effect against UV compared to deionized (DI) water, that RH was not a factor in stability of MS2 coli phage sprayed in AS or BE, and that infectious MS2 particles in DI water displayed a volume-based size distribution but in AS and in BE the size dependence was of a lower order. Whereas AS and BE enhanced stability, adding salts had the opposite effect.