After one year of research accounts, finally the CDC updates recommendations on COVID-19 airborne transmission

Schematic representation of the respiratory system with the corresponding penetration of particles of different sizes. Photo credit: University of Kentucky

On Friday, May 7, the United States Centers for Disease Control and Prevention (CDC) released new public recommendations to consider airborne coronavirus disease 2019 (COVID-19) transmission. The CDC is now considering both the transmission of the SARS-CoV-2 virus and an infection that causes COVID-19 disease, which can be caused by inhaled fine bioaerosol particles from the respiratory tract.

The new guidelines are fully in line with the Scientific Perspectives, which are one year old at this point. In contrast to airborne transmission, the CDC’s previous official statement was that most infections were from close contact with large droplets and formites. Back on April 7, 2020, a novel perspective from Marcelo Guzman, a chemistry professor at the University of Kentucky with a PhD in environmental and engineering. Caltech’s deal was preprinted to persuade scientists and public health officials to pay serious attention to the SARS-CoV-2 threat in the air. A second version of the preprint was later published on April 22nd and finally peer-reviewed on December 8th in the International Journal of Health Planning and Management for the publication of an open access journal. This work clearly explained the danger of small bioaerosol particles that over time can remain in the air and penetrate different levels of the respiratory system.

To outline the recent changes, the CDC claims there is a risk associated with inhaling the virus because it is transmitted on exposed mucous membranes, as well as by touching the mucous membranes directly with dirty hands contaminated with virus. The effects are directly applicable to indoor spaces such as workplaces, schools, and public transportation that lack adequate ventilation or air purification systems. Many follow-up studies published last semester have shown the role that small bioaerosol particles play in human health. For example, a recently published open access paper in the International Journal of Environmental Research and Public Health, which was published in January, included a list of recommendations for preventing airborne transmission of the SARS-CoV-2 virus. The study recommended efforts to control the spread of the virus caused by ventilation in restaurants, cruise ships, nursing homes, schools, kindergartens, offices, shops and public transport to combat the pandemic. The use of suitable personal protective equipment, mechanical air filters, ultraviolet germicidal radiation (UVGI), high efficiency particle air filters (HEPA) and ion generators were recommended.

Efforts to stop the spread of COVID-19 should focus on preventing airborne transmission

More information:
Marcelo Guzman, Bioaerosol Size Effect in COVID-19 Transmission, April 7, 2020,, DOI: 10.20944 / preprints202004.0093.v1.

Marcelo I. Guzman, Bioaerosol size effect in COVID-19 transmission, April 22, 2020,, DOI: 10.20944 / preprints202004.0093.v2.

Marcelo I. Guzman. An overview of the effect of bioaerosol size on coronavirus disease transmission 2019, The International Journal of Health Planning and Management (2020). DOI: 10.1002 / hpm.3095

Mahdieh Delikhoon et al. Modes of Transmission of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and Factors Affecting Airborne Transmission: An Overview, International Journal of Environmental Research and Public Health (2021). DOI: 10.3390 / ijerph18020395

Provided by the University of Kentucky

Quote: After a year of research reports, the CDC is finally updating the COVID-19 Airborne Transmission Recommendations (2021 May 15), published on May 15, 2021 from cdc- were retrieved. covid-airborne.html

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