I am starting to understand our differences of opinion. In your last post you stated that you feel that COVID is a droplet and fomite transmitted infection. I feel the evidence suggests it is predominantly airborne, probably predominantly aerosol.
The CDC specifically says it does not think fomite transmission is the predominant method of COVID transmission, it feels "close contact" and airborne are the predominant forms of transmission (1)
Aerosols, not merely droplets, have more recently been felt, by numerous international scientists and studies (2,3), to have a major role in transmission, and the WHO has agreed (4). You certainly are aware of the church choir event in Washington (5). Recently, aerosolized fomites have been implicated, which would still be primarily a form of respiratory transmission (6).
IF we can’t agree on the predominant mode of transmission then we won’t agree on the proper way to prevent the infection! I merely point out that you seem to be the outlier (both in this country and elsewhere in the world); the burden of proof falls on you to demonstrate the predominance of fomite (as opposed to respiratory) transmission.
Redirection does lower viral concentration in the air in front of the person wearing the mask, as their plume of exhaled air is dispersed up, down, to the right, and to the left, rather than straight ahead. It will not lower the total number of viruses in the room, but will lower the concentration inhaled by those who are not “distant”, those who the maskless person is breathing at. I think you will agree the lower the concentration of virus in the inhaled air, the lower the risk of infection. It is not recommended to wear a mask when more than 6-10 feet from someone. Social distancing has been shown to reduce the spread of COVID in the US (7). Being outdoors is felt to reduce transmission due to dilution of the exhaled (and then inhaled) virus.
Second hand smoke does not cause contagious respiratory disease so it is not a good apples to apples analogy.
Regarding inoculum, the papers by Gandi (9) and Gullar (10) have multiple references to clinical severity relating to dose. While I do not want to get into that can of worms, you and your readers may find the discussions useful since respiratory transmission, etc., is discussed at length with numerous references.
I am for using science. The principles of respiratory infection control have been proven, and include distancing, hand washing, and masks (for epidemics and pandemics, testing and contact tracing as well). Locations that utilize those principles have had success in combating COVID and other pandemics. Those principles are not an arbitrary custom, they work. To change those principles and programs in the middle of the pandemic seems like a mistake. Many of the issues regarding anxiety, hostility, etc would be improved with consistent messaging and teaching.
It would be interesting trying to create a study comparing mask use with no change in distancing or handwashing to truly understand the incremental benefit of each. The behavioral effects of mask wearing makes that difficult. Our open society also makes that difficult, as participants would be in contact with those not participating, even if cities and states were randomized.
The informed consent would say something like, “Most successful respiratory infection control programs feel that an essential component is wearing a mask. We have not demonstrated that wearing a mask is an important part of the program compared to hand washing and distance. In this trial you and everyone else you come in contact with will not be wearing a mask. This may put you and those around you, including your loved ones, at increased risk to spread a significant and deadly disease compared to those in the “usual program” group, whereby you and others will wear a mask when within 6 feet of each other.” Good luck with that study!!
This is very different than setting up a study saying that “There is significant disagreement in the world of surgery regarding site shaving for surgery. If you are randomized to shaving you with a razor vs using electric clippers, you (and only you) may have a greater or lesser chance of getting a wound infection”.
Not every intervention has level one evidence. Doctors are allowed to go “off label” for medications. Masks are a mechanical barrier, not even a systemic medication. Designing studies indeed take social and behavioral issues into account, and, importantly, whether or not there is clinical equipoise. You have not demonstrated that there is widespread clinical equipoise regarding mask use, you are saying there is not enough evidence to meet your standards, and because of that you would like to change proven methods of managing respiratory epidemics/pandemics.
I agree that complications of masks as far as I know have not been formally studied. Their benefit in the OR to protect either the patient or the wearer is not universally accepted. However, they have been used by many thousands of people every day since they were first used in 1897 in surgery (8) and in industry, and until COVID I’m not aware of issues regarding their safety. I agree-if you don’t look you will not find, and there may be occupational self-selection going on. But they are part of successful COVID infection control programs, with a logical rationale and proof of clinical effectiveness (when part of a program of distance, washing, and masks). They are not a random, stand alone intervention.
You believe fomites are the major source of COVID transmission. There is not significant scientific or medical agreement with your position to warrant a change in a successful infection control programs, at least In any country that I am aware of. If you are correct those data may yet come.
The discussion of how long to continue a proven program is another interesting topic, related to social norms, societies value of individual lives, quality of life, and the economic and emotional consequences of proven disease mitigation strategies. That is also where open and honest discussion comes in.
I don’t have an answer to the second wave question, other than many people since March have been distancing, and many are outside, and many are wearing masks. It will be interesting (unfortunately) to see what happens as the weather gets colder and holidays encourage more indoor large gatherings.
1) https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/how-covid-spreads.html
2) Numerous references contained in: Lidia Morawska, Donald K Milton, It is Time to Address Airborne Transmission of COVID-19, Clinical Infectious Diseases, , ciaa939, https://doi.org/10.1093/cid/ciaa939
3) https://www.ecdc.europa.eu/en/covid-19/latest-evidence/transmission
5) https://www.cdc.gov/mmwr/volumes/69/wr/mm6919e6.htm
6) Asadi, S., Gaaloul ben Hnia, N., Barre, R.S. et al. Influenza A virus is transmissible via aerosolized fomites. Nat Commun 11, 4062 (2020). https://doi.org/10.1038https://www.nature.com/articles/s41467-020-17888-w
7) Strong Social Distancing Measures In The United States Reduced The COVID-19 Growth Rate
8) Da Zhou C, Sivathondan P, Handa A. Unmasking the surgeons: the evidence base behind the use of facemasks in surgery. J R Soc Med. 2015;108(6):223-228. doi:10.1177/0141076815583167
9) Gandhi, M., Beyrer, C. & Goosby, E. Masks Do More Than Protect Others During COVID-19: Reducing the Inoculum of SARS-CoV-2 to Protect the Wearer. J GEN INTERN MED (2020). https://doi.org/10.1007/s11606-020-06067-8
10) "Inoculum at the time of SARS-CoV-2 exposure and risk of disease severity": Gullar MP, Meirino, R, Donat-Vargas, C, et al. https://www.sciencedirect.com/science/article/pii/S1201971220304707
Sorry I misunderstood your opinions about fomite transmission, we agree that while it may possible, it is unlikely a common form of transmission!
Regarding the U Wash link you provided (https://huddle.uwmedicine.org/news/uw-medicine-responds-recommendation-partners-health-system-regarding-ppe):
It is a policy for UW Medicine, not the general population.
It assumes controlled access, appropriate screening performed by and for motivated individuals, and importantly, “Rapid access to testing for SARS-CoV-2 continues to be of paramount need throughout the country and is not uniformly available in all locations. Within UW Medicine, we have access to quick and reliable testing in the UW Virology Laboratory that enables us to safely isolate and evaluate our patients.”
Unfortunately, these assumptions are not valid for the general population.
In fact, the University of Washington (general population) requires masks indoors and even outdoors when unable to maintain 6 foot distance (https://www.ehs.washington.edu/face-covering-requirements).
I have not decided a priori that masks work. I have agreed with you, the data is not great. But masks are part of standard public health programs to fight respiratory viruses. Those programs are effective. There has been essentially no flu is South America this season, because of distance, washing, and masks (https://www.scientificamerican.com/article/flu-season-never-came-to-the-southern-hemisphere/ ).
Please tell me if the standard public health recommendations for a respiratory virus epidemic/pandemic is not, distance, hand washing, and masks. What we don’t know is how effective each component is individually. Among other things the behavioral effects of masks make individual components difficult to separate.
I look at the effectiveness of the standard public health programs and say, “Why do masks seem to be effective?”, you look and say, “No RCD so ignore them.”
BTW, in another post you referred to my “cronies”. My posts are mine, written when I have the time. I do not watch CNN or Fox. In deference to your request as Blog host, I will have a HCQ response when I can. Thank you for the discussion.