Method for Evaluating the Relative Efficiency of Selected N95 Respirators and Surgical Masks to Prevent the Inhalation of Airborne Vegetative Cells by Healthcare Personnel

Davidson, Craig S.; Green, Christopher F.; Panlilio, Adelisa L.; Jensen, Paul; Stover, Beth H.; Roselle, Gary A.; Gibbs, Shawn G.; Scarpino, Pasquale V.

doi:10.1177/1420326x10378805

Cited by 5 publications

(4 citation statements)

References 40 publications

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“…In a study of Bacillus anthracis, the relative efficiency (i.e., the percent reduction of a test manikin's inspired concentration of test aerosol when wearing the device compared to not wearing the device) of surgical and N95 masks ranged from 34 to 65% [63]. In a similar study, the relative efficiency of surgical masks and surgical N95 respirator masks ranged from 34 to 67% and 34 to 62% respectively, while N95 respirator masks had relative efficiency of 66 to 69% [64].…”

Section: Surgical Masks and Respiratorsmentioning

confidence: 83%

A Systematic Literature Review of Indoor Air Disinfection Techniques for Airborne Bacterial Respiratory Pathogens

Nguyen

Johnson

Bell

et al. 2022

IJERPH

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Interrupting the transmission of airborne (<≈5 µm) respiratory pathogens indoors is not a new challenge, but it has attracted unprecedented interest due to the COVID-19 pandemic during 2020–2021. However, bacterial respiratory pathogens with known or potential airborne transmission account for an appreciable proportion of the communicable disease burden globally. We aimed to systematically review quantitative, laboratory-based studies of air disinfection techniques for airborne respiratory bacteria. Three databases (PubMed, Web of Science, Scopus) were searched, following PRISMA guidelines. A total of 9596 articles were identified, of which 517 were assessed in detail and of which 26 met the inclusion and quality assessment criteria. Seven air disinfection techniques, including UV-C light, filtration, and face masks, among others, were applied to 13 different bacterial pathogens. More than 80% of studies suggested that air disinfection techniques were more effective at inactivating or killing bacteria than the comparator or baseline condition. However, it was not possible to compare these techniques because of methodological heterogeneity and the relatively small number of the studies. Laboratory studies are useful for demonstrating proof-of-concept and performance under controlled conditions. However, the generalisability of their findings to person-to-person transmission in real-world settings is unclear for most of the pathogens and techniques we assessed.

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Section: Surgical Masks and Respiratorsmentioning

confidence: 83%

A Systematic Literature Review of Indoor Air Disinfection Techniques for Airborne Bacterial Respiratory Pathogens

Nguyen

Johnson

Bell

et al. 2022

IJERPH

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“…We used previously described methods to measure the arrestance of bioaerosols by surgical masks (C. S. Davidson, C. F. Green, A. L. Panlilio, P. A. Jensen, S. G. Gibbs, and P. V. Scarpino, unpublished manuscript). 8,9 Vegetative cells and endospores of Bacillus anthracis Sterne strain (nonencapsulated, viable B. anthracis strain Sterne 34F2; Colorado Serum) were prepared, using standard techniques. 10 " 12 Bacillus anthracis was used for convenience; its use was not meant to imply that this bacterium is spread from contagious patients through the airborne route.…”

Section: A T E R I a L And M E T H O D Smentioning

confidence: 99%

“…All studies were conducted in a horizontal bioaerosol chamber, which was described in previous studies. 8 ' 9,1617 Figure 1 shows the placement ofthe collision nebulizer, the AGI-30 samplers, and the mannequin in the bioaerosol chamber. The nebulizer was turned on for 8 min to allow the chamber to reach a steady state before sampling was performed.…”

Section: A T E R I a L And M E T H O D Smentioning

confidence: 99%

Effectiveness of Selected Surgical Masks in Arresting Vegetative Cells and Endospores When Worn by Simulated Contagious Patients

Green

Davidson

Panlilio

et al. 2012

Infect. Control Hosp. Epidemiol.

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Objective.The objective of this study was to quantify the effectiveness of selected surgical masks in arresting vegetative cells and endospores in an experimental model that simulated contagious patients.Setting.Laboratory.Methods.Five commercially available surgical masks were tested for their ability to arrest infectious agents. Surgical masks were placed over the nose and mouth of mannequin head forms (Simulaids adult model Brad CPR torso). The mannequins were retrofitted with a nebulizer attached to an automated breathing simulator calibrated to a tidal volume of 500 mL/breath and a breathing rate of 20 breaths/min, for a minute respiratory volume of 10 L/min. Aerosols of endospores or vegetative cells were generated with a modified microbiological research establishment-type 6-jet collision nebulizer, while air samples were taken with all-glass impinger (AGI-30) samplers downstream of the point source. All experiments were conducted in a horizontal bioaerosol chamber.Results.Mean arrestance of bioaerosols by the surgical masks ranged from 48% to 68% when the masks were challenged with endospores and from 66% to 76% when they were challenged with vegetative cells. When the arrestance of endospores was evaluated, statistical differences were observed between some pairs, though not all, of the models evaluated. There were no statistically significant differences in arrestance observed between models of surgical masks challenged with vegetative cells.Conclusions.The arrestance of airborne vegetative cells and endospores by surgical masks worn by simulated contagious patients supports surgical mask use as one of the recommended cough etiquette interventions to limit the transmission of airborne infectious agents.

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“…Thus, engineering methods for disinfection of airborne infectious microorganisms are crucial to prevent transmission of these diseases, particularly in highrisk settings and susceptible populations [15]. These facts demonstrate the importance of respiratory protection using personal protective equipment such as respirators coated with antimicrobial materials [3,8,11,33].…”

mentioning

confidence: 99%

Survival of Microorganisms on Antimicrobial Filters and the Removal Efficiency of Bioaerosols in an Environmental Chamber

Kim

Kim²,

Lee³

et al. 2012

J. Microbiol. Biotechnol.

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Exposure to bioaerosols causes various adverse health effects including infectious and respiratory diseases, and hypersensitivity. Controlling exposure to bioaerosols is important for disease control and prevention. In this study, we evaluated the efficacies of various functional filters coated with antimicrobial chemicals in deactivating representative microorganisms on filters or as bioaerosols. Tested functional filters were coated with different chemicals that included (i) Ginkgo and sumac, (ii) Ag-apatite and guanidine phosphate, (iii) SiO 2 , ZnO, and Al 2 O 3 , and (iv) zeolite. To evaluate the filters, we used a model ventilation system (1) to evaluate the removal efficiency of bacteria (Escherichia coli and Legionella pneumophila), bacterial spores (Bacillus subtilis spore), and viruses (MS2 bacteriophage) on various functional filters, and (2) to characterize the removal efficiency of these bioaerosols. All experiments were performed at a constant temperature of 25ºC and humidity of 50%. Most bacteria (excluding B. subtilis) rapidly decreased on the functional filter. Therefore, we confirmed that functional filters have antimicrobial effects. Additionally, we evaluated the removal efficiency of various bioaerosols by these filters. We used a six-jet collision nebulizer to generate microbial aerosols and introduced it into the environmental chamber. We then measured the removal efficiency of functional filters with and without a medium-efficiency filter. Most bioaerosol concentrations did not significantly decrease by the functional filter only but decreased by a combination of functional and medium-efficiency filter. In conclusion, functional filters could facilitate biological removal of various bioaerosols, but physical removal of these by functional was minimal. Proper use of chemical-coated filter materials could reduce exposure to these agents.

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Method for Evaluating the Relative Efficiency of Selected N95 Respirators and Surgical Masks to Prevent the Inhalation of Airborne Vegetative Cells by Healthcare Personnel

Cited by 5 publications

References 40 publications

A Systematic Literature Review of Indoor Air Disinfection Techniques for Airborne Bacterial Respiratory Pathogens

A Systematic Literature Review of Indoor Air Disinfection Techniques for Airborne Bacterial Respiratory Pathogens

Effectiveness of Selected Surgical Masks in Arresting Vegetative Cells and Endospores When Worn by Simulated Contagious Patients

Survival of Microorganisms on Antimicrobial Filters and the Removal Efficiency of Bioaerosols in an Environmental Chamber

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