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Inspecting a High-Profile Study on Face Masks for Controlling Coronavirus

I have spent considerable time studying research articles on or about the use of face masks to control the spread of COVID-19.

Image symbolizing the search for evidence compiled by Robert G. Kernodle

Image symbolizing the search for evidence compiled by Robert G. Kernodle

High Quality Research?

The journal, Nature Medicine, is the most cited research journal in pre-clinical medicine. Someone citing an article from this journal gives a convincing appearance of presenting high quality research. Unfortunately, just because an article appears in a prestigious journal does not mean that the person citing the article knows what the article really means. This can lead to the person’s failure to apply the article in a correct manner. Such is the case with an article that I will discuss below.

My aim here is to look at specific language used by researchers to describe their study on the effectiveness of face masks to control the transmission of coronavirus. This requires presenting a number of exact quotes, followed by my own discussion of the content of these quotes.

The quotes appear as bulleted italics paragraphs, followed by my clarification of the language and its relevance to the issue of forced mass masking of asymptomatic people to control COVID-19 (the alleged disease caused by the alleged SARS-CoV-2 novel coronavirus).

The Study

Screen capture of Leung et al title page as it appears in "Nature Medicine"

Screen capture of Leung et al title page as it appears in "Nature Medicine"

This was a randomized study, using real people, in real time, with real outward symptoms of illness.

___________________________________________________________________
Leung, N.H.L., Chu, D.K.W., Shiu, E.Y.C. et al (2020). Respiratory Virus Shedding in Exhaled Breath and Efficacy of Face Masks. Nature Medicine 26:676–680.

___________________________________________________________________

  • Our results indicate that surgical face masks could prevent transmission of human coronaviruses and influenza viruses from symptomatic individuals.

The word, could, means maybe or maybe not. Leaders would be making a grave mistake to translate the word, could, as the word, can, to justify sweeping societal policies based on the resulting erroneously implied certainty.

Take special note of the fact that the human subjects of this study all had physical symptoms of illness. There were no asymptomatic subjects in this study. The study, therefore, cannot be applied to a general population of asymptomatic people.

  • Although hand hygiene and use of face masks, primarily targeting contact and respiratory droplet transmission, have been suggested as important mitigation strategies against influenza virus transmission, little is known about the relative importance of these modes in the transmission of other common respiratory viruses. Uncertainties similarly apply to the modes of transmission of COVID-19.
  • There is little information on the efficacy of face masks in filtering respiratory viruses and reducing viral release from an individual with respiratory infections, and most research has focused on influenza.

In the above two sentences, the authors identify the current limited knowledge of disease transmission and face masks.

  • Here we aimed to explore the importance of respiratory droplet and aerosol routes of transmission with a particular focus on coronaviruses, influenza viruses and rhinoviruses, by quantifying the amount of respiratory virus in exhaled breath of participants with medically attended ARIs [Acute Respiratory Illnesses – for example, the common cold] and determining the potential efficacy of surgical face masks to prevent respiratory virus transmission.

In this (above) sentence, the authors clarify the focus of their study, which is to explore viral transmission via respiratory droplets and aerosol routes specifically, in an attempt to add to the limited state of knowledge that they clearly pointed out earlier.

  • Viral RNA was identified from respiratory droplets and aerosols for all three viruses, including 30%, 26% and 28% of respiratory droplets and 40%, 35% and 56% of aerosols collected while not wearing a face mask, from coronavirus, influenza virus and rhinovirus-infected participants, respectively.

As written, this sentence is tangled and hard to understand. Untangled and stated more clearly, it means the following:

In Symptomatic Individuals Breathing Normally

Without Masks

  • 30% of coronavirus respiratory droplets registered viral RNA
  • 26% of influenza respiratory droplets registered viral RNA
  • 28% of rhinovirus respiratory droplets registered viral RNA
  • .
  • 40% of coronavirus aerosols registered viral RNA
  • 35% of influenza aerosols registered viral RNA
  • 56% of rhinovirus aerosols registered viral RNA

But those percentages state only one side of the observation, where the other (unstated) side of the observation of symptomatic individuals breathing normally without masks is this:

  • 70% of coronavirus droplets did not register viral RNA
  • 74% of influenza droplets did not register viral RNA
  • 72% of rhinovirus droplets did not register viral RNA
  • .
  • 60% of coronavirus aerosols did not register viral RNA
  • 65% of influenza aerosols did not register viral RNA
  • 44% of rhinovirus aerosols did not register viral RNA

The key here is to realize that the majority of droplets and aerosols in symptomatic people did not register viral RNA, yet the authors have chosen to assign the idea of significance only to the lower percentage, as if to imply that a small percentage should dictate over a larger percentage, where formulating conclusions is concerned.

It would make little sense to automatically attribute even these percentages to people who show zero symptoms, yet this study is often cited (erroneously) to justify mass masking of asymptomatic individuals.

Detection-Infection Dilemma

Continuing with key quotes from the study:

  • We detected coronavirus in respiratory droplets and aerosols in 3 of 10 (30%) and 4 of 10 (40%) of the samples collected without face masks, respectively, but did not detect any virus in respiratory droplets or aerosols collected from participants wearing face masks, this difference was significant in aerosols and showed a trend toward reduced detection in respiratory droplets.

This sentence is also hard to understand, as written. Broken up and stated more clearly, it means:

  • 30% of breath samples collected from symptomatic people without face masks contained coronavirus in their respiratory droplets
  • 40% of breath samples collected from symptomatic people without face masks contained coronavirus in their aerosols
  • 0% of breath samples collected from symptomatic people with face masks contained coronavirus

The authors focus on the 40% of symptomatic people without face masks in whom they detected coronavirus, but say nothing about the 60% of symptomatic people without face masks in whom they detected no coronavirus.

These observations raise the important question, Why did 60% (the majority) of symptomatic people without face masks show no coronavirus shedding, while 40% did? Would this not indicate a very important fact – that some people with symptoms shed coronavirus, while some people (the majority) with symptoms do not shed coronavirus? Such a very important question gets no consideration at this point. Instead, the weight of the observation leans in favor of the minority of symptomatic people who did shed coronavirus.

Mass masking assumes that everybody sheds virus the same. It assumes that all people without symptoms shed virus, and that all people without symptoms shed virus equally. The study here, remember, does not even apply to people without symptoms, and even the majority of people with symptoms (60%) in the study did not shed coronavirus.

Consequently, how anyone could cite this study as evidence to support mass masking of asymptomatic people is beyond any measure of rational thinking. This study, simply and clearly offers no such evidence.

Symptomatic Participants Who Did Not Shed Virus

The authors state:

  • We also demonstrated the efficacy of surgical masks to reduce coronavirus detection and viral copies in large respiratory droplets and in aerosols.

The above statement applies to 40% of symptomatic people in the study who shed virus, but it does not apply to 60% of symptomatic people in the study who did not shed virus, because there was no detectable virus in that 60% for masks to reduce.

In other words, the findings favor 40% of symptomatic people who shed and offer no conclusions about the 60% of symptomatic people who did not shed virus.

Extrapolating a minority observation about symptomatic people to the majority of people in society that have no symptoms, again, would be beyond any measure of rational thinking. This study simply and clearly offers no evidence that mass masking of asymptomatic people makes sense.

  • This has important implications for control of COVID-19, suggesting that surgical face masks could be used by ill people to reduce onward transmission.

Notice ill people – people who show outward, physical symptoms of illness. Also notice that the claim applies only to 40% of those symptomatic people (ill people) of the study in whom viral shedding was even detected without masks. What indication do we have that 60% of symptomatic people in whom viral shedding was not detected should be forced to wear masks? The authors show little consideration for this majority. People who latch onto this study as evidence likewise misrepresent the majority of people in their analysis.

  • Among the samples collected without a face mask, we found that the majority of participants with influenza virus and coronavirus infection did not shed detectable virus in respiratory droplets or aerosols, whereas for rhinovirus we detected virus in aerosols in 19 of 34 (56%) participants (compared to 4 of 10 (40%) for coronavirus and 8 of 23 (35%) for influenza).

This is one of the most confounding statements in the entire article, where the authors themselves finally make clear what I pointed out earlier, regarding their percentages. Consider exactly what they are saying – the majority of symptomatic participants without face masks did not shed detectable coronavirus.

I will state that again: the majority of participants with symptoms and without face masks did not shed detectable coronavirus.

  • For those who did shed virus in respiratory droplets and aerosols, viral load in both tended to be low.

Even the relatively few symptomatic participants without face masks who did shed coronavirus shed a low viral load of it. Would a rational society allow a few people to dictate the lives of the many? Do we know that these few are shedding active viruses that could actually infect others? Or might they be shedding markers of inactive viruses?

  • Given the high collection efficiency of the G-II [a bio-aerosol collecting device] and given that each exhaled breath collection was conducted for 30 min, this might imply that prolonged close contact would be required for transmission to occur, even if transmission was primarily via aerosols, as has been described for rhinovirus colds.

In other words, unmasked, symptomatic people breathing for thirty minutes could not generate very much coronavirus. So, yes, this would imply that prolonged close contact would be required for transmission of coronavirus to occur.

This observation, therefore, cannot serve as justification for masking entire populations of people without symptoms.

  • Our results also indicate that there could be considerable heterogeneity in contagiousness of individuals with coronavirus and influenza virus infections.

The word, heterogeneity, means diversity or difference. Considerable heterogeneity, then, means considerable difference, and, in this context, it means that different individuals shed viruses differently. Different individuals infect other individuals differently. Everybody is not equal in terms of their potential to infect others. Everybody is not equal in terms of their potential to get infected by others.

Mass masking of entire populations operates under the assumption that everybody, whether symptomatic or not, sheds infectious virus and sheds it in the same way, in the same amount.

This study again clearly reveals that it cannot apply to entire populations, where both asymptomatic and symptomatic individuals exist. The study does not focus on asymptomatic individuals – it is biased in favor of a smaller percentage of symptomatic individuals. Citing it as evidence for entire populations of outwardly healthy people, therefore, is invalid.

Outstanding Study Limitations

The authors plainly point out:

  • The major limitation of our study was the large proportion of participants with undetectable viral shedding in exhaled breath for each of the viruses studied.

Yes, this limitation becomes clear to anyone who takes time to understand exactly what the numbers mean. This limitation is certainly critical, to the point of invalidating the entire study as evidence to justify forcing people to wear face masks.

  • Another limitation is that we did not confirm the infectivity of coronavirus or rhinovirus detected in exhaled breath. … we did not attempt to culture coronavirus or rhinovirus from the corresponding aerosol samples.

Stating this limitation as if it were acceptable grossly understates the severity of such a limitation. This limitation fundamentally renders the entire study fatally incomplete, where even its tentative conclusions rest on nothing substantial.

Determining whether what was detected actually caused the observed infections would seem to be the most critical step in such a study. But the researchers clearly state that they did not attempt to culture coronavirus or rhinovirus from any samples of exhaled breath.

How, then, could the researchers possibly know that they were dealing with infectious respiratory droplets or infectious aerosols? They simply could not know, because they made no attempt to know.

So, here we have a study of symptomatic individuals, the majority of whom did not shed detectable coronavirus, where those who did shed detectable coronovirus did so at low viral loads, the infectiousness of which the researchers never confirmed.

This is what many people cite as research justifying forced mass masking of entire populations, regardless of whether people are symptomatic or asymptomatic.

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