‘Zombie deer disease’ epidemic spreads in Yellowstone as scientists raise fears it may jump to humans

Lee Duna@lemmy.nz to News@lemmy.world – 426 points –
‘Zombie deer disease’ epidemic spreads in Yellowstone as scientists raise fears it may jump to humans
theguardian.com
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Oh its totally fine it's not like we've made the planet warmer allowing viruses to mutilate easier and for longer or like how we haven't been taking part in a centuries long destruction of the deers native habitat forcing them into populated areas right?... Right?

It's not a virus.

I mean, doesn't that reinforce their point, since many other pathogens are even more touchy on heat?

It's actually worse than a virus.

Once an environment is infected, the pathogen is extremely hard to eradicate. It can persist for years in dirt or on surfaces, and scientists report it is resistant to disinfectants, formaldehyde, radiation and incineration at 600C (1,100F).

The pathogen in question is a prion (a mutant contagious protein molecule)

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Biologist here. That’s not where I’d put the association. I’m going to simplify things a bit because this is going to be a long post, but hopefully this will help.

I think you’re thinking about the effects of heat on proteins. We can destabilize macromolecules by heating them, sometimes causing permanent damage. That takes a lot of heat, though. The planet would be long dead before we had to worry about the environmental temperature denaturing proteins.

Biologist related joke: How do you unscramble an egg?
Feed it to a chicken.

So, when the microscope was invented, people were startled to discover what were obviously living organisms in a drop of pond water. Discovery led to discovery, and we ended up learning about bacteria and the germ theory of disease. Some bacteria are really good (in that without them you would die), and some are really bad (like if you get infected you could die), but most are neutral. I do not believe there’s any direct connection between the global temperature and the rate of mutation in bacteria. That’s not to say there’s not a connection between climate change and disease rates. I’ll talk about that later.

So later on we discovered viruses. Viruses are much smaller than bacteria. While a bacterium is a cell with a whole physiology going on, a virus consists of a bit of genetic material bound in an envelope of proteins. The envelope will gain access to a cell and inject its genetic material, which the cell’s normal processes will start to work on, producing more viruses. Many people don’t consider viruses “alive.” I do, because I’m approaching it from a different direction. Again, the rate of mutation there isn’t really directly affected by a rise in global temperature, but there is a disease rate relationship.

We only discovered prions more recently. They’re even more simple than viruses. They’re really just a protein. We don’t understand them very well yet. The danger comes from the fact that prions can force other proteins to become copies of themselves. They can cause things like mad cow disease. They’re incredibly hardy and don’t mutate faster because of climate change. They’re very scary diseases with no known treatment and in some cases unknown transmission paths.

This one is a prion.

I think we can find correlations between disease in animals and climate change. Climate change forces animals into new environments where they can encounter diseases they’ve never faced before and to which they’re susceptible.

Even more important is the common root cause of industrialization and human expansion and environmental destruction. Again, forcing more animals together magnifies the impact of communicable diseases, and things like the use of antibiotics to make factory farming as profitable as possible has the inevitable consequences of making diseases that are harder to treat.

Thanks for the ELI5.

Apart from ingestion, are there any other known methods of transmission as far as prions are concerned?

One of the problems is that we don’t know. It might be environmental contamination (eg deposits on grass or in soil). Ebola patient 0 was thought to be a toddler-aged child who ate a piece of fruit that had been contaminated by dung from an infected bat (Ebola, like many of our diseases, is zoonotic). It’s also thought to potentially come from preparing meat from an infected animal. If it’s in the environment, it may also come from some social behavior, like grooming or wound cleaning. Could it be transmitted by parasites that jump from host to host drinking blood? No idea. I’m just spitballing based on how some other diseases become density dependent.

Prions are absolutely fascinating. I really hope they make a lot of progress.

Not this pathogen. Prions are not living organisms, not even as much as viruses, and are extremely resistant to both heat and cold. It's the same stuff that caused the mad cow disease in Britain.

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