This old CDC guidance on transmission, versus the new:
a thread
@CDCDirector @CDCgov @CDCemergency @CDC_eHealth @CDCGlobal @CDC_NCEZID
You ***really*** missed a spot with aerosol transmission.
@bsmithtampabay @jhaskinscabrera

Allow me to dive into critical oversights. 1/

On May 7, you updated guidance to basically omit all prior guidance that this was a droplet-based pathogen. But WHY is this important?

Because all national mitigation efforts have been focused on solely droplet, especially at our test sites and with our most vulnerable 2/

This is especially of concern when our TEST SITES are following droplet-based mitigation, breathing concentrated plumes of fine particulates directly over testing materials as those most likely to be in contact with novel pathogen.

Hand sanitizer won’t fix that. 3/

This is huge, as it explains your asymp/presymp spread issue. The person most likely in contact with novel pathogen breathing a concentrated plume directly onto materials then stuck INTO oral/nasal mucosa; PCR thresholds too high to indicate live viral matter?

Huge issue 4/

We have all of this verbiage regarding mucosal transmission without inclusion of ocular protection or a word of the nasolacrimal apparatus.

Where is the guidance that 90% of respiratory emissions are in that fine particulate range, and that droplet can BECOME aerosol?

5/

It gets into inhalation being key transmission route, but fails to address masks as a source of spread due to concentrated plumes of fine particulate, which INCREASES TRAJECTORY.

6 feet over or 6 feet under is dead - but the message on protecting the vulnerable is lacking 6/

The pivot toward dilution/destruction was beginning to happen, and begins to address plosive force generating activities and plosive respiration, while failing to address the involvement of masks in exacerbation of spread through pressurized plumes, aerosolization of droplet
7/

In an enclosed space, one transmissible positive has enough viral load in 1 breath to infect everyone in that space.

This is a low minimum infective dose pathogen, and just slowing down a pathogen that *remains aloft* within respiratory range increases atmospheric viral load
8/

Many estimate minimum infective dose - the going dose people claim is between 10-100, as high as 1000 virions for transmission. It isn’t a constant, as neither is our state of health as a populous.
We are all very different.

Are you going to stop pushing hand sanitizer yet? 9/

See again this part about well-fitting masks? Sure, the higher grade respirators that have a minimal protective value (which none of you are wearing) can help protect the wearer, but STOP touting masks as source control.

10/

This is what two cloth masks look like. This is not effective source control for airborne pathogen. These are expressly non-PPE non-mitigating apparatuses with up to 97% particle penetration of fine particulates.
Second photo is fitted single cloth. 11/

A technical of mine on how masks exacerbate the spread of airborne pathogen and come with a host of severe physiological impacts including hypoxia, hypercapnia, and pathogenic and fibrous inhalation.

Masks are not source control.
#RationalGround
https://docs.google.com/file/d/1KZVV_5WUQcDXXeLIW9mhAGGEpKhpXWRY/edit?usp=docslist_api&filetype=msword

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@PanData19 @robinmonotti2 @andrewbostom @Emily_Burns_V