Thread by @LazarusLong13

August 2020. Conly, Seto, @DidierPittet, @Metadoc publish this commentary on behalf of the WHO IPC group.

Let's see what they got wrong. And if either of the tagged gentlemen beg to differ? I always bring the receipts - but you have to go first.

aricjournal.biomedcentral.com/articles/10.11…

Wrong. Near field aerosols are the greatest risk, and those go out to 2 meters.

Majority of transmission is by those with ZERO symptoms.

Risk assessment? Do asbestos crews do those? Coal miners? BSL3 lab workers?

Also, filtration

does reduce near and far field aerosols. But what doctor knows what ACH is in what room in their hospital? Or if the filtration is even turned on? Or if it's even any good (ahem, UK hospitals)?

Droplets produce fomites? Proof? What studies - Covid only.

On the other hand, we know that the majority of viral load comes from fine aerosols, sub 5 micron.

Stands to reason that would be the source of the particles on fomites as well.

So many mistakes.

Airborne aerosols are up to 100 microns.

AGMPs generate far few aerosols than people. Period. Go argue with Klompas on this. In the other pic? They forgot breathing, yelling, whispering, singing, crying, etc.

A medical mask is not considered by NIOSH to be proper PPE for respiration.

Period.

BLS3 labs, working on CoVid, have N95s as base PPE despite having even better filtration than hospitals.

Lol. Respiratory droplets are dominant?

Live by the epi pattern, die by the epi pattern.

80% of China's 1.4 billion infected within one month by droplets?

Those are some magical droplets....

contagionlive.com/view/-80-of-ch…

So....transmission occurred mostly in families in close contact with each other.

In a nation that had mandatory masking everywhere outside of their homes, and massive lockdowns, so people were even MORE exposed to each other in their homes, which have poor ventilation.

Ah....

But they only had a SAR of 3-10%.

Yawn. 28.3%–46.7% for Omicron. 15.9%–23.1%% for ancestral (what they measured).

Of course, Conly et al did not share what they considered to be adequate for household SAR. Just that it had to be the same as measles.

Which is stupid, to be blunt.

Measles is easy to measure, because of the...red dots, as @JOHNJOHNSTONED so cleverly pointed out, so long ago.

COVID, quite often with a lack of surface symptoms or even seroconversion? Much more difficult to measure.

R0..... Oh, let's play their RNaughty game. Measles is 10.

Delta is 3.2 to 8.

Omicron is 3.19 times Delta.

Let's do the lowest figure. Oh. 10 for CoVid, too!

#CovidIsAirborne ?

Next, they used the example of very little spread of Covid on an airplane ride where there were exactly two infected people - who were wearing masks!

But...because it's not possible for them to eat and drink wearing a mask, or because the filtration wouldn't last 15 hours?

Maybe the WHO IPC committee should tell HCWs putting in 18 hour days their N95s won't last. Because surgical masks and N95s actually have the same basic filtration.

Also? They only monitored those within 2 meters. Despite monitoring the ENTIRE PLANE for measles.

You can't

Measure what you don't measure.

Additionally, in regards to the PCR tests were more fraught with error at that time.

Next, another case where everyone wore masks and respirators near someone infected with a not very contagious disease.

Airborne - but not very contagious.