Well we don't really know that, because diagnosis is normally confirmed post-mortem. There could be many people walking around infected with prions that show no symptoms at all.

There's some pedantry here.

There is evidence that some people have a mutation that prevents them from getting CJD. The mutation causes a small change in the proteins that CJD prions impact (changing a glycine to valine at a certain part of the protein). The working theory is that that structural change prevents CJD prions from being able to re-form healthy proteins, preventing the spread of the disease. I wouldn't be at all surprised if those proteins are eventually broken down by the body and removed.

All that being said, I don't know if you would even consider it an "infection" if the person is immune to the prions spreading. Prions aren't generally transmissible, so if the prions don't do anything and can't be transmitted... is anything actually wrong? You and I are exposed to tons of bacteria every day, but as long as your body can fight it off (i.e. no symptoms and no transmission), we wouldn't usually call that an "infection". In the same light, presence of abnormal proteins that aren't causing an issue doesn't seem like something we would call an "infection".

There's also the fact that some people inherit the disease (as in their body actually makes the prions itself), which doesn't make any sense in the context of an "infection". It's their own body producing the prions, so in those cases it's a genetic disease, not an infection.

Avoid eating British beef in the 1980s/1990s, too.

Apparently 1 in 2,000 people in the UK may be infected.[0]

We still don't know if there's going to be a second wave of disease from infections from that time period due to genetic factors influencing incubation of the disease.

This is why people who were in the UK for longer than a few months during the 80s and 90s aren't allowed to give blood in various places around the world.

[0] https://www.bbc.co.uk/news/health-24525584

And don't feed beef to cows.

I was there with the mad cow disease. Not in the UK, but in Spain, as commerce inside the EU made people truly paranoid on eating meat from "untrusted" sources.

Scary, really scary.

Serious question should I be avoiding traveling to the UK over this??

Nope, but do avoid eating any British people over the age of 20.

No, that was 20-30 years ago.

At this point, the best prevention is to avoid eating anyone who lived in Britain 20-30 years ago

You forgot anyone who ate anyone who lived in Britain 20-30 years ago.

Hopefully that's something we can all agree upon!

The mediation HCG is processed from pregnant women’s urine and has been shown to potentially contain prions. I took it for years. Yay.

The sad thing is there’s a recombinant version that would be safe, but it also costs thousands of dollars.

>Avoid cannibalism and you should be fine.

And animal brains, and the areas around experimental research labs...

Also see dura mater grafts: https://www.cdc.gov/mmwr/volumes/67/wr/mm6709a3.htm

And avoid being in the same room with someone that’s been infected:

In a 2011 paper, his team reported that prions can spread through aerosols

Not unless someone is literally sneezing their brains out.

There's still uncertainty about whether or not CJD can be spread through blood transfusions, but if it is spread through blood, and the sneezer also has a bloody nose, well there's the aerosol transmission.