From Droplets to "Through the Air": Why Ventilation and Respirators Matter More Than Ever in Infection Prevention

View OpEd: https://www.infectioncontroltoday.com/view/droplets-through-air-why-ventilation-respirators-matter-more-than-ever-infection-prevention

References:

1. World Health Organization, Leading health agencies outline updated terminology for pathogens that transmit through the air. WHO. April 18, 2024. https://www.who.int/news/item/18-04-2024-leading-health-agencies-outline-updated-terminology-for-pathogens-that-transmit-through-the-air

2. National Academies of Sciences, Engineering, and Medicine. 2020. Airborne Transmission of SARS-CoV-2: Proceedings of a Workshop—in Brief. Washington, DC: The National Academies Press. https://www.nationalacademies.org/publications/25958

3. Santarpia JL, Herrera VL, Rivera DN, et al. The size and culturability of patient-generated SARS-CoV-2 aerosol. J Expo Sci Environ Epidemiol. 2022 Sep;32(5):706-711. doi: 10.1038/s41370-021-00376-8. Epub 2021 Aug 18. PMID: 34408261; PMCID: PMC8372686. https://pmc.ncbi.nlm.nih.gov/articles/PMC8372686/

4. Aryal S. SARS-CoV-2 Structure & Genome: Key Proteins & RNA Features. Microbe Notes. Jan. 11, 2025. https://microbenotes.com/structure-and-genome-of-sars-cov-2/

5. Tankeshwar A. Infective dose (ID) and Lethal Dose (LD). Microbe Online. Mar. 1, 2022. https://microbeonline.com/infective-dose-and-lethal-dose/

6. Mølbak K, Sørensen TIA, Bhatt S, et al. Severity of respiratory tract infections depends on the infectious dose. Perspectives for the next pandemic. Front Public Health. 2024 Apr 30;12:1391719. doi: 10.3389/fpubh.2024.1391719. PMID: 38746005; PMCID: PMC11091249. https://pmc.ncbi.nlm.nih.gov/articles/PMC11091249/

7. Gandhi M, Rutherford GW. Facial Masking for Covid-19 - Potential for "Variolation" as We Await a Vaccine. N Engl J Med. 2020 Oct 29;383(18):e101. doi: 10.1056/NEJMp2026913. Epub 2020 Sep 8. PMID: 32897661; PMCID: PMC7890559. https://pmc.ncbi.nlm.nih.gov/articles/PMC7890559/

8. Reuters Fact Check. Fact Check: No evidence Omicron BA.5 is more infectious than measles or is 'the most infectious virus known. Reuters. July 15, 2022. https://www.reuters.com/article/fact-check/no-evidence-omicron-ba5-is-more-infectious-than-measles-or-is-the-most-infecti-idUSL1N2YW1T0/
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9. Sanche S, Lin YT, Xu C, Romero-Severson E, Hengartner N, Ke R. High Contagiousness and Rapid Spread of Severe Acute Respiratory Syndrome Coronavirus 2. Emerg Infect Dis. 2020 Jul;26(7):1470-1477. doi: 10.3201/eid2607.200282. Epub 2020 Jun 21. PMID: 32255761; PMCID: PMC7323562. https://pmc.ncbi.nlm.nih.gov/articles/PMC7323562/

10. Biggerstaff M, Cauchemez S, Reed C, Gambhir M, Finelli L. Estimates of the reproduction number for seasonal, pandemic, and zoonotic influenza: a systematic review of the literature. BMC Infect Dis. 2014 Sep 4;14:480. doi: 10.1186/1471-2334-14-480. PMID: 25186370; PMCID: PMC4169819. https://pmc.ncbi.nlm.nih.gov/articles/PMC4169819/

11. Lai J, Sobhani H, Coleman KK, et al. Evaluating modes of influenza transmission (EMIT-2): Insights from lack of transmission in a controlled transmission trial with naturally infected donors. PLoS Pathog. 212. Airborne Contaminant Removal. https://pubmed.ncbi.nlm.nih.gov/41499634/

12. CDC Infection Control. Appendix B. Air. Airborne Contaminant Removal. Table B.1. Air changes/hour (ACH) and time required for airborne-contaminant removal by efficiency. Jan. 11, 2024. https://www.cdc.gov/infection-control/hcp/environmental-control/appendix-b-air.html

13. CDC Measles (Rubeola). How Measles Spreads. April 18, 2024. https://www.cdc.gov/measles/causes/index.html

14. CDC Measles (Rubeola). About Measles. May 29, 2024. https://www.cdc.gov/measles/about/index.html

15. Mahase E. WHO urged to make respirator masks the standard for workers in "all healthcare settings". BMJ. 2026 Jan 9;392:s52. doi: 10.1136/bmj.s52. PMID: 41513258. https://www.bmj.com/content/392/bmj.s52.full

16. Lay K. Face masks ‘inadequate’ and should be swapped for respirators, WHO is advised. The Guardian. Jan. 9, 2026. https://www.theguardian.com/global-development/2026/jan/09/health-professionals-respirator-grade-masks-who-advise

17. Morawska L, Li Y, Salthammer T. Lessons from the COVID-19 pandemic for ventilation and indoor air quality. Science. 2024 Jul 26;385(6707):396-401. doi: 10.1126/science.adp2241. Epub 2024 Jul 25. PMID: 39052782. https://www.science.org/doi/10.1126/science.adp2241

18. Zhang N, Liu C, Hou C. et al. The impact of indoor carbon dioxide exposure on human brain activity: A systematic review and meta-analysis based on studies utilizing electroencephalogram signals. Building and Environment. July 1, 2024. https://www.sciencedirect.com/science/article/abs/pii/S0360132324005298

19. ASHRAE Publishes Standard 241, Control of Infectious Aerosols. July 7, 2023. https://www.ashrae.org/about/news/2023/ashrae-publishes-standard-241-control-of-infectious-aerosols