Thread by @1goodtern

You might think that public health bodies and institutions and their leaders know what they're talking about, but, sadly, they often just regurgitate garbage fake science that has no actual basis in fact, but sometimes it's more sinister than that.

Here's an example, shared a couple of weeks ago by the American Society of Microbiology.

It includes a claim (a lie, actually, but we'll come to that) that you might have seen repeated a lot during the last few years.

The *lie* that "80% of all infectious diseases are passed by human contact, direct or indirect".

Yes, I'll get round to why it's a lie.

But, first, let's explain why it's wrong.

The first way of knowing that it's wrong is that it's obviously not something that you can know.

Because no one has ever measured this stuff.
No one has tracked the transmission methods of all infectious disease.

It's obviously an unknowable statistic.

And secondly it's not a sentence with a clear meaning.

Does it mean 80% of infections, or 80% of diseases?

Does it mean that 80% can be passed that way, or that 80% are passed that way?

And how universal is this statistic?
Does it apply to places where the primary threats of disease are from conditions that are airborne?

Does it apply equally to a modern city with excellent sanitation as it does to a slum?
Does it apply in the cold climates the same way as it does in the hot ones?

Wet, dry, crowded, clean, remote, high traffic, sunny, windy, dispersed, seaside, industrial, low income, age demographics.

When you look at the statement for *a fraction of a second* you realise that it obviously can't be true because a) it doesn't mean anything, and b) it doesn't mean anything.

But what *is that statement trying to do*?

It's trying to influence your thinking.

Yes.

There's another way that you can tell that the claim is dodgy.

Every time you encounter it, the claim will be slightly different.

Almost as if they know that it's obviously not quite right, so they shift their weasel words...
Take this example in a blog post for the National Foundation For Infectious Diseases.

(And when they say 'for', I really do strongly suspect they mean 'for'.)

"This is especially important since health experts know that more than 80% of illnesses can be transmitted by the hands."

Wait... was it that "80% of all infectious diseases are passed by human contact, direct or indirect"
or "more than 80% of illnesses can be transmitted by the hands"?

or is it "about 80% of infectious diseases are spread by dirty hands"?

Or is it that "about 80% of infectious diseases are transmitted by unclean hands touching contaminated surfaces"

Do you see that all of these are different?

Or is it that "80% of all infections are transmitted by hands"?

Here's another society in favour of infectious diseases telling you that "according to estimates by the Centers for Disease Control and Prevention (CDC), approximately 80% of common infectious illnesses are spread through hand contact."

You've got public health bodies on every continent sharing this as if it's fact.

Every time it's different.

It never ever ever ever includes a link to a full definition of the statement.

It never ever ever ever includes a link to a study.

The claim is most commonly dragged out on 15th October each year.

Why?

Because that's international handwashing day.

Whether you're in Lubbock, Lithuania, Latvia, Lviv, Lusitania, Libya, or Lima, you're going to get told this claim by your public health authorities and institutions to get you to wash your hands.

You'll get told it by people with impressive sounding names and titles.

Like "James Arbogast, PhD, Vice President of Hygiene Sciences and Public Health Advancements, GOJO Industries"

Wait, what did you say?

What industries?

Aaaah.

Gojo industries.

The people who make Purell.

That's right.

It's a marketing claim.
Advertising.

Also known as *a lie*.

It has no basis in any research ever.

Go do a search.

I've been reading through study after study after study trying to find any basis for the claim, and there's none anywhere.

Nothing at all.
Zip.
Zero.

It's funny.
Sometimes blogs include a link or a reference to the CDC saying some variation of the "80%" claim.

But there's never anything there.

It's just a health meme, picked up out of the ether by the people who make hand sanitiser, and then pumped out to as many people as it can taint with the message.

At every new transmission of the meme, the meme shifts subtly to back up whichever message someone is trying to push at the time.

It *always* downplays the role of other modes of transmission, obviously, because it's a lie used to get you to concentrate on your hands.

Don't get me wrong.

It's really good to wash your hands.

More people need to wash their hands.

Healthcare workers in this country seem to be ditching it entirely.
It's a nightmare.

But what's actually happening here is that public health is being done by internet meme.

Inaccuracy.
Exaggeration.
Distortion.
Misdirection.

That's the opposite of how to do public health.

And the real world result is that the garbage lie just gets re-parroted endlessly and forever by people who don't even spend a second thinking.

https://x.com/ShannonMcKenney/status/1987774627268198645?s=20