What were the historical reasons for the resistance to recognizing airborne transmission during the COVID-19 pandemic?

Jose L Jimenez; Linsey C Marr; Katherine Randall; Edward Thomas Ewing; Zeynep Tufekci; Trish Greenhalgh; Raymond Tellier; Julian W Tang; Yuguo Li; Lidia Morawska; Jonathan Mesiano-Crookston; David Fisman; Orla Hegarty; Stephanie J Dancer; Philomena M Bluyssen; Giorgio Buonanno; Marcel G L C Loomans; William P Bahnfleth; Maosheng Yao; Chandra Sekhar; Pawel Wargocki; Arsen K Melikov; Kimberly A Prather

doi:10.1111/ina.13070

What were the historical reasons for the resistance to recognizing airborne transmission during the COVID-19 pandemic?

Indoor Air. 2022 Aug;32(8):e13070. doi: 10.1111/ina.13070.

Authors

Jose L Jimenez¹, Linsey C Marr², Katherine Randall³, Edward Thomas Ewing⁴, Zeynep Tufekci⁵, Trish Greenhalgh⁶, Raymond Tellier⁷, Julian W Tang⁸, Yuguo Li⁹, Lidia Morawska¹⁰, Jonathan Mesiano-Crookston¹¹, David Fisman¹², Orla Hegarty¹³, Stephanie J Dancer¹⁴, Philomena M Bluyssen¹⁵, Giorgio Buonanno¹⁶, Marcel G L C Loomans¹⁷, William P Bahnfleth¹⁸, Maosheng Yao¹⁹, Chandra Sekhar²⁰, Pawel Wargocki²¹, Arsen K Melikov²¹, Kimberly A Prather²²

Affiliations

¹ Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA.
² Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia, USA.
³ Department of English, Virginia Tech, Blacksburg, Virginia, USA.
⁴ Department of History, Virginia Tech, Blacksburg, Virginia, USA.
⁵ School of Journalism, Columbia University, New York, New York, USA.
⁶ Department of Primary Care Health Sciences, Medical Sciences Division, University of Oxford, Oxford, UK.
⁷ Department of Medicine, McGill University, Montreal, Québec, Canada.
⁸ Department of Respiratory Sciences, University of Leicester, Leicester, UK.
⁹ Department of Mechanical Engineering, University of Hong Kong, Hong Kong, China.
¹⁰ International Laboratory for Air Quality and Heath, Queensland University of Technology, Brisbane, Queensland, Australia.
¹¹ Goldman Hine LLP, Toronto, Ontario, Canada.
¹² Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
¹³ School of Architecture, Planning & Environmental Policy, University College Dublin, Dublin, Ireland.
¹⁴ Department of Microbiology, Hairmyres Hospital, Glasgow, and Edinburgh Napier University, Glasgow, UK.
¹⁵ Faculty of Architecture and the Built Environment, Delft University of Technology, Delft, The Netherlands.
¹⁶ Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, Italy.
¹⁷ Department of the Built Environment, Eindhoven University of Technology (TU/e), Eindhoven, The Netherlands.
¹⁸ Department of Architectural Engineering, The Pennsylvania State University, University Park, Pennsylvania, USA.
¹⁹ College of Environmental Sciences and Engineering, Peking University, Beijing, China.
²⁰ Department of the Built Environment, National University of Singapore, Singapore, Singapore.
²¹ Department of Civil Engineering, Technical University of Denmark, Lyngby, Denmark.
²² Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA.

Abstract

The question of whether SARS-CoV-2 is mainly transmitted by droplets or aerosols has been highly controversial. We sought to explain this controversy through a historical analysis of transmission research in other diseases. For most of human history, the dominant paradigm was that many diseases were carried by the air, often over long distances and in a phantasmagorical way. This miasmatic paradigm was challenged in the mid to late 19th century with the rise of germ theory, and as diseases such as cholera, puerperal fever, and malaria were found to actually transmit in other ways. Motivated by his views on the importance of contact/droplet infection, and the resistance he encountered from the remaining influence of miasma theory, prominent public health official Charles Chapin in 1910 helped initiate a successful paradigm shift, deeming airborne transmission most unlikely. This new paradigm became dominant. However, the lack of understanding of aerosols led to systematic errors in the interpretation of research evidence on transmission pathways. For the next five decades, airborne transmission was considered of negligible or minor importance for all major respiratory diseases, until a demonstration of airborne transmission of tuberculosis (which had been mistakenly thought to be transmitted by droplets) in 1962. The contact/droplet paradigm remained dominant, and only a few diseases were widely accepted as airborne before COVID-19: those that were clearly transmitted to people not in the same room. The acceleration of interdisciplinary research inspired by the COVID-19 pandemic has shown that airborne transmission is a major mode of transmission for this disease, and is likely to be significant for many respiratory infectious diseases.

Keywords: airborne transmission; disease transmission; droplet transmission; history.

Publication types

Review
Research Support, Non-U.S. Gov't

MeSH terms

Air Pollution, Indoor*
COVID-19*
Humans
Pandemics
Respiratory Aerosols and Droplets
SARS-CoV-2

Grants and funding

WT_/Wellcome Trust/United Kingdom