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. 2021 May 7;4(2):e275.
doi: 10.1002/hsr2.275. eCollection 2021 Jun.

Droplets and aerosols: An artificial dichotomy in respiratory virus transmission

Yannis Drossinos  1 , Thomas P Weber  2 , Nikolaos I Stilianakis  1   3
Affiliations

Droplets and aerosols: An artificial dichotomy in respiratory virus transmission

Yannis Drossinos et al. Health Sci Rep. .

Abstract

In the medical literature, three mutually non-exclusive modes of pathogen transmission associated with respiratory droplets are usually identified: contact, droplet, and airborne (or aerosol) transmission. The demarcation between droplet and airborne transmission is often based on a cut-off droplet diameter, most commonly 5 μm. We argue here that the infectivity of a droplet, and consequently the transmissivity of the virus, as a function of droplet size is a continuum, depending on numerous factors (gravitational settling rate, transport, and dispersion in a turbulent air jet, viral load and viral shedding, virus inactivation) that cannot be adequately characterized by a single droplet diameter. We propose instead that droplet and aerosol transmission should be replaced by a unique airborne transmission mode, to be distinguished from contact transmission.

Keywords: SARS‐CoV‐2; aerosols; airborne; droplets; influenza; respiratory pathogens; transmission mode.

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Conflict of interest statement

The authors declare there is no conflict of interest.

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