I received this email indirectly -
"Here's my take related to the articles you've sent thus far. I hope you'll accept this, but I'm seeing some pseudo-science. (I know, I sound like Trump and fake news.) What bothers me is Dr. Stephen's lack of well-written responses to the data contained in peer-reviewed articles (although admittedly, I don't have time to investigate the sources right now to determine if they are truly credible.) "
The writer is referring to my post on surgical masks. In that post, I cited the Annals of Internal Medicine and the CDC. One doesn't get any more mainstream than that. I am happy to answer questions on specific articles or data. I reviewed the available literature. There are no good data on surgical masks. If there were, the Annals and the CDC would have published or discussed them. Discussing (I guess ironically now) that a hair salon in Missouri had no infections after everyone wore a mask and two hair stylists had Covid isn't a study; it's an anecdote and the CDC put that story forward as if it meant something (it didn't). It wasn't even close to a scientific study.
Again, the HCQ data are much stronger than any mask data. The Indian HCQ pre-exposure prophylaxis study was controlled and they tested subjects with RT-PCR assay, the most sensitive assay for detecting infection. The original virologic clearance study by Dr. Raoult's group was controlled as well, albeit not randomized controls. My point on the data is to show that people are representing the quality of data differently based upon their views and not based upon the reality of the quality of those data.
One cannot simultaneously claim that the surgical mask data are strong and the HCQ data are weak.
That is what we call in Mathematics, absurd.
https://en.wikipedia.org/wiki/Reductio_ad_absurdum
SMS
We both agree that COVID patients are contagious. Most feel they are contagious in the asymptomatic, presymptomatic, and/or minimally symptomatic period.
Masks don't stop transmission, masks reduce transmission. They protect you from me when I may not realize I am infected.
Surgical masks deflect and disperse droplets and aerosols. When in close proximity (<6-10ft) this may be important as it keeps the plume emanating from my mouth and nose from getting directly into your inhaled air, allowing more time and space for dilution and inactivation of the virus.
There is evidence that masks are effective in reducing transmission of respiratory viruses. Prior to COVID there was no real disagreement that masks are part of the solution for fighting respiratory viruses. A successful public health program includes isolation, testing, contact tracing, hand washing, and masks. The incremental benefit of the individual components can be debated and is hard to define. Most countries (political allies of the US as well as enemies and frenemies) accept that conclusion.
Recent data suggests that the above methods, now in widespread use because of COVID, have contributed to the especially mild flu season in South America (1,2,3). On cruise ships mask have reduced infection and symptoms of COVID (4, 5).
There is little if any risk from wearing masks. Until the COVID controversy, I was not aware of serious health concerns regarding surgical masks. Thousands of people have worn them all day for years (surgeons, anesthesiologists, nurses, industrial workers, etc) without serious issues. If there were serious concerns, please let me know.
Fomite transmission from the mask is a theoretical risk, but fomite transmission is general does not seem to be a big problem with COVID. Given the large number of people wearing masks, it probably would have been an issue with mask use and other respiratory viruses, for which fomite transmission seems to be more important.
It would be better if mask data was from randomized trials rather than epidemiological, observational, and/or model-based evidence. However, it seems foolhardy to ignore one aspect of established programs that have been successful in reducing infections without clear and convincing evidence to the contrary. Maybe we will move to that point with regard to masks, but it seems most ID and epidemiology experts do not feel we are there at this point.
I disagree with the assertion that there is damning evidence in the study claiming to show that putting a mask on after a family member is sick doesn't reduce infection. The mask is supposed to be on the infected one, not the others. Part of the problem with mask studies is all of the confounding variables, and these are no exception.
One benefit of wearing masks is that they remind everyone to be careful!
Controlling for that particular variable is difficult, especially given the variety of masks and how they are worn, but that social factor could partially account for why places that mandate masks seem to have lower infection rates.
Risks like anxiety, violence, etc. could be better managed with a clear, consistent, and coordinated message from elected leaders and public health officials, as has been done in other countries.
Masks do not need to be worn in cars, walking apart outside, walking alone outside, etc. They should be worn when unable to keep "social distance", ie: they should be worn when there may be unpreventable, accidental, or intentional close interactions with people outside of your household or "pod". They should be worn inside public places to catch and diffuse (some, but not all) droplets, and to catch and diffuse (some, but not all) aerosols. Masks should be disposable or washed every day.
The law of unintended consequences extends to the consequences of doing nothing, such as anxiety from helplessness, etc. during a pandemic.
We have to make choices regarding which consequences we are willing accept. Does the general public want to trade some discomfort to avoid some illness and death, or would it rather risk some illness and death to avoid some discomfort? If so, how much and what kind of discomfort vs how much illness and death?
This is why effective, honest, and consistent leadership and education is so important.
I agree that people should not be in each other's faces regarding masks, but I also think it is reasonable that masks be mandated inside, or in places where people may be in close proximity and breathing on each other, even unintentionally.
1. https://www.who.int/influenza/surveillance_monitoring/updates/latest_update_GIP_surveillance/en/
2. https://www.advisory.com/daily-briefing/2020/07/24/coronavirus-restrictions
3. https://www.sciencemag.org/news/2020/08/how-will-covid-19-affect-coming-flu-season-scientists-struggle-clues
4. Masks Do More Than Protect Others During COVID-19: Reducing the Inoculum of SARS-CoV-2 to Protect the Wearer; https://link.springer.com/article/10.1007/s11606-020-06067-8
5. https://www.ucsf.edu/news/2020/07/418181/one-more-reason-wear-mask-youll-get-less-sick-covid-19