Monday 6 July 2020

Is the coronavirus airborne?


You might have seen this news article:

239 experts with 1 big claim: The coronavirus is airborne

In an open letter to the WHO, 239 scientists in 32 countries have outlined the evidence showing that smaller particles can infect people with Covid-19 and are calling for the agency to revise its recommendations.

06 July, 2020 
NEW YORK — The coronavirus is finding new victims worldwide, in bars and restaurants, offices, markets and casinos, giving rise to frightening clusters of infection that increasingly confirm what many scientists have been saying for months: The virus lingers in the air indoors, infecting those nearby.
If airborne transmission is a significant factor in the pandemic, especially in crowded spaces with poor ventilation, the consequences for containment will be significant. Masks may be needed indoors, even in socially distant settings. Health care workers may need N95 masks that filter out even the smallest respiratory droplets as they care for coronavirus patients.


The problem is reading "scientific" evidence is not plain nor simple. From the article: "239 scientists in 32 countries have outlined the evidence showing that smaller particles can infect people..."
So if you are reading that in plain English, there is only one possible reaction: PANIC!
But you should ask, "what does "can infect" mean?"

If someone with the virus sneezes or coughs in a room and then leaves the room, and then 100 people just walk through the room every 5 seconds (without touching anything), and ALL 100 people get infected, OBVIOUSLY you CAN get infected. 

If out of the 100 people only 1 person got infected, isn't it also correct to state that you CAN get infected via airborne droplets? 

Is the first scenario the same as the second?

The word "can" means "possible" here. Hence, this rebuttal:
"we have been stating several times that we consider airborne transmission as possible but certainly not supported by solid or even clear evidence,”
Which the dissenting scientists feel is too conservative: "the infection prevention and control committee in particular, experts said, is bound by a rigid and overly medicalised view of scientific evidence, is slow and risk-averse in updating its guidance and allows a few conservative voices to shout down dissent."

But surely (IMHO) if WHO is risk-averse, they would be overly conservative in their guidelines and cover ALL possible risks? WHO response tells me that rather than reacting to sensational or alarmist claims, they choose to examine the facts, and THEN give an informed opinion advised by facts and proof.

But some want the WHO to "relax its criteria for proof, especially in a fast-moving outbreak."
Relax the criteria for proof? Translation: Become the National Enquirer? Accept any "facts" at face value? Don't bother testing and re-testing assertions of "facts"?
Why?

Because, "Scientists have not been able to grow the coronavirus from aerosols in the lab. But that doesn’t mean aerosols are not infective..."
In other words, some basic attempts to test the hypothesis failed. But this has NOT changed the minds of the detractors, and instead they want WHO to change their standards of proof?
So what (else) do the detractors want?
For 
"WHO [to] embrace what some called a “precautionary principle” and others called “needs and values” — the idea that even without definitive evidence, the agency should assume the worst of the virus, apply common sense and recommend the best protection possible.
“There is no incontrovertible proof that SARS-CoV-2 travels or is transmitted significantly by aerosols, but there is absolutely no evidence that it’s not,” said Dr Trish Greenhalgh, a primary care doctor at the University of Oxford in Britain."
I have highlighted the important phrases ("without definitive evidence", "assume the worst", etc)"... So basically WHO should just act like a panicky housewife responding to gossip? (Apologies to panicky housewives... oh. There's only one of you.)

Those are not phrases that a scientist or an expert uses. Any scientist can tell you that it is NOT possible to prove a negative ("no evidence that it's not") so for a doctor to make that logical fallacy says something about that doctor's logical process.

[Basically, if you conduct 100 tests to see if the virus is transmissible by air, and 100 times the experiment found NO transmission/infection, a scientist would NOT say that he has proven that air transmission is NOT possible. He would only state that in 100 experiments, there were no transmission detected. He MIGHT conclude, that it is highly improbable for airborne infection, but he cannot say that it is impossible. Which WHO has also stated: "we consider airborne transmission as possible but certainly not supported by... evidence."]

And what is "Best Protection Possible"? At this point, I would think a full-face diving mask and a scuba tank.

But the point here is not to convince anybody of any position. If you believe that the virus is airborne, by all means protect yourself the best way you believe you need to. If you believe WHO is a useless organisation, why listen to them. Do as you believe. Donald Trump does. And he's POTUS. You would be in good company.

On the other hand, if you prefer to respond moderately and with deliberation, and after considering the facts and evidence (and you can select which evidence you think is pertinent), and take educated (or calculated) risks, then by all means do so.

So let me summarise.

239 experts claim that the coronavirus is transmissible by air, by aerosol droplets that linger in the air for a long time after the infected has left.

WHO accepts that airborne transmission is possible. But not supported by evidence.

The dissenting experts therefore want WHO to "relax its criteria for proof". From this you can deduce that the 239 experts have some proof, but WHO does not view their "proof" as sufficient evidence. So they want WHO to relax their standards? Doesn't sound fishy to me at all!

Scientists have not been able to grow the coronavirus from aerosol. 

BUT this does not prove that aerosols are NOT infective! (How many times must I tell you, you cannot prove a negative! And it seems like their entire argument is based on: I can't prove I'm right, but you cannot prove I'm wrong, so why don't you accept that I am right?)



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