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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How NOT to Science. A time travel thread and magic.
This is Helmut Traindl - the engineer who devised the procedure behind Walach CO2 study that was retracted after 16 days: jamanetwork.com/journals/jamap…
I looked at your thread @moog77 . The reason that epidemiological didn't work (cases continued to go up)? Is the same reason the 2023 Cochrane fails, ironically, after you touted it as the "gold standard."
Not because clean air doesn't reduce cases. It empirically does. It
Got a "oops, outside air can get you" study. Coming out of Beijing University of Technology - taking airborne transmission seriously.
They rented 50 rooms of a building. Did some very cool CFD work - then, be still my heart,
followed it up with tracer gas experimentation.
See room 303 above? 403 and 503 got whatever came out of 303.
With studies like these, there are so many variables. But, if I lived in an apartment, I would set have at least a PC fan CR Box next to those open windows.
Or an HRV set up in that window. And for sure a PC fan CR box next to the front door for under the door airflow.