Always a great study when tweeted out by Dr. Noakes - let's dive in.
✅2 cases of transmission from bus drivers to passengers up to more than 9 feet/ 3 meters.
✅Genomic confirmation
✅Airflow traced - please see Dr. Noakes original thread for commentary on the method used.
Limitations:
📌Facemask compliance unsure
📌Fomite possible. Not likely
📌Community transmission possible - but not likely
Two trips and two separate van drivers involved.
Both trips - windows closed, ventilation NOT on recirculate, heaters on medium fan.
First trip - 4 patients on 2-hour trips to and from the hospital on December 2, 2020. Driver tested +positive on December 3, 2020.
Van below.
Driver had a high viral burden: 15.9
Driver and all passengers wore cloth facemasks and only interacted during boarding and transportation.
Second trip - The second driver transported 3 patients on the same 2-hour trip in the same van on
January 23, 2021, the day his symptoms began.
Van below.
Driver viral load was high - 24.
Driver was not in a mask, but the passengers were.
What everyone is most interested in - airflow tracing.
Heater on? Smoke released from the driver seat at headrest height rose and flowed toward the back of the van.
When heater and fans were off, no "microspheres" were recovered from the seats or air.
Next tweet method...
I don't remember seeing this exact technique before in any of the studies I've read. Not saying it's not valid at all. Just haven't seen it.
Contact Tracing Method
Genomic Method.
Our take-aways?
👉 #CoVidIsAirborne.
👉 #BetterMasks are necessary.
👉 If you open diagonal windows, you can create an air curtain. Like in this case, passenger and the window directly behind the driver.
In this case, that last bullet point was not possible due to passenger
windows not being able to be opened.
H/T @linseymarr for the air curtain suggestion about 1 million pandemic years ago!
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DYK that you, and me, and everybody are Pig Pen from Charlie Brown?
We shed our entire outer layer of skin every 2-4 weeks, about 500 million cells daily.
Your corneocytes (outermost cells) lift off of your body with the
gentlest of micro-air currents. Like a leaf picked up off the ground for the briefest of moments in fall.
They act like 12 micron aerosols in float time, but 25% of total skin flakes are sub 5 microns...and you know what that means. Deep deposition - or shallow as
sub 5 likes to also deposit in the nose.
It's funny...I embrace push-back in debate. Tightens up my game.
Imagine if those skin flakes now have Ebola on them?
Two studies show that Ebola literally oozes through the skin - both ways. In and out.
"...due to the desirability of an off-
the-face design, and not for protection from aerosols, respirators may be used instead of medical masks"who.int/publications/i…
If you can stay 3 feet away while screening? No medical mask needed.
PCDH1 (protocadherin-1) is primarily expressed in the airway epithelium of the respiratory system, especially in the bronchial and nasal epithelial cells, and in pulmonary endothelial cells.