Thread: Masks and NPIs.
This thread reviews information published from Oct 2019 - Dec 2020.
The point is to see what was known/believed before & after discovery of COV2.
We'll start with research on epidemic/pandemic influenza (flu) from Oct of 2019.
Aerosols vs. droplets.
/1
Seasonality? This was actually a known phenomenon?
/2
Intended impact of NPIs.
Does this look familiar? This published in October of 2019 - that's very interesting to me.
Why does this "flatten the curve" image always go to 0 with no resurgence and not have values on either axis?
Let's look at NY and FL for fun.
/3
Evaluation of the evidence.
Order of quality (best to worst):
1) Randomized Controlled Trials (RCTs)
2) Observational Studies
3) Computer Simulations
How many RCTs have been done since COV2? None? DANMASK?
How about the CDC review of 14 RCTs covering NPIs in the community?
/4
Summary of Recommendations.
Masks?
For Asymptomatic:
Conditionally recommended "although there is no evidence that this is effective in reducing transmission"
For Symptomatic:
Recommended always despite no evidence
Why? Mechanistic plausibility.😐
/5
Surface and object cleaning?
Recommended at all times "although there is no evidence this is effective in reducing transmission."
Why? Mechanistic plausibility.😐
Contact tracing?
NOT RECOMMENDED
/6
Quarantine/Isolation?
Sick Individuals:
Recommended at all times but very low quality of evidence.
Exposed Individuals (not sick):
"no obvious rationale for this measure"
NOT RECOMMENDED
/7
School measures and closures?
Conditionally recommended with very low quality of evidence.
Should only be for a limited period of time with all adverse effects fully considered first.
/8
Personal Protective Measures.
Hand Hygiene?
Apparently, RCTs have not found hand hygiene to be effective against flu in community settings. I did not know this. Did you?
This only works theoretically and experimentally, so again its down to mechanistic plausibility.
/9
Masks?
"There was no evidence that face masks are effective in reducing transmission of laboratory-confirmed influenza."
Why then does this same entity conditionally recommend wearing of masks by asymptomatic people?
"mechanistic plausibility."
No mention of the harms.
/10
Now, we jump to May 2020.
Different entity saying the same thing.
"these measures did not support a substantial effect on transmission of laboratory-confirmed influenza"
Despite what? Mechanistic plausibility...
/11
What changed for COV2? Why did Fauci say masks should not be worn only to then do a 180* and start acting like they were magic?
This defied all known science except "mechanistic plausibility."
Did they all mistake correlation for causation while ignoring seasonality?
/12
1 month later to June 2020.
By now, masks had gone from obscure to mandated for general public.
This is acknowledged while stating such mask usage is not supported by evidence.
However, it still recommends masks due to...correlation seen in recent observations (Mar-May).
/13
Evidence?
None for "the effectiveness of universal masking of healthy people in the community to prevent infection with respiratory viruses"
Potential Benefits?
"reduced potential exposure"
Then
- Reduced stigmatization
- Virtue
- Compliance
- Source of income
😐
/14
Potential Harms?
- Self-contamination due to touching mask and face/eyes
- Self-contamination due to improper use, amplifying microorganism growth
- Headaches / breathing difficulties
- Skin lesions
- Communication, especially children, deaf, & developmentally challenged
/15
Now, Dec 2020. Did anything change?
Evidence?
No new supporting evidence, but the language was changed from
"there is no direct evidence"
to
"there is only limited and inconsistent scientific evidence"
Basically...there's no evidence, but we keep recommending anyway.
/16
Benefits?
Mostly the same except they reworded the "compliance" bullet. Still have virtue listed.
It specifically references reduced spread of "droplets" without mentioning aerosols.
Also claims masks prevent TB and Flu but does not provide a reference with evidence.
/17
Harms?
2 strange changes:
1) First, both of the "self-contamination" bullets were removed. Why? There went from first on the list to non-existent
2) Added a very interesting one: "a false sense of security"
/18
Guidance?
In the end, "despite the limited evidence of efficacy of mask wearing in community settings," they still advise mask wearing.
😐
/19
This is enough to force children to wear masks of random materials for many hours each day?
This is enough to scare people into not only wearing masks wherever they go but even wearing 2?
We must stop. Don't be fooled. Don't let yourself be coerced into compliance.
/20
References.
WHO (Oct 2019):
apps.who.int/iris/bitstream…
CDC (May 2019):
wwwnc.cdc.gov/eid/article/26…
WHO (Jun 2020):
apps.who.int/iris/bitstream…
WHO (Dec 2020):
who.int/publications/i…
/END
BONUS
In the vein of "correlation-as-causation" with observational studies, this happened in November.
A team at UCSF, including @MonicaGandhi9 - who I wish to enter a dialogue with - withdrew a pre-print that was originally going to correlate mask mandates w/ decreased Hosps.
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