"long period of uncertainty began on 31 May 2010, when she stabbed her left thumb with a curved forceps while cleaning a cryostat—a machine that can cut tissues at very low temperatures—that she used to slice brain sections from transgenic mice infected with a sheep-adapted form of BSE. She pierced two layers of latex gloves and drew blood"
Later in the article:
""We conduct research only on mouse-adapted sheep prions, which have never been shown to be infectious to humans,” Aguzzi [neuropathologist at the University of Zurich] says."
It sounds like the assumption that mouse-adapted sheep prions can't infect humans may be flawed.
> Emilie is therefore working that day on samples of mice infected with strains of human prions. It is important to stress here that these were human strains and not animal strains, the species barrier no longer protecting, the infectivity of the pathogens handled by Emilie was therefore total.
> Emilie travaille donc ce jour là sur des échantillons de souris infectées avec des souches de prions humaines. ll est important de souligner ici qu'il s'agissait de souches humaines et non de souches animales, la barrière d'espèce ne protégeant plus, l'infectiosité des pathogènes manipulés par Emilie était donc totale.
(In case anyone else wanted to double-check the translation.)
The full section with the Aguzzi quote adds context, including his declining to comment on the French case.
> The scientific community has long recognized that handling prions is dangerous and an occupational risk for neuropathologists, says neuropathologist Adriano Aguzzi of the University of Zurich. Aguzzi declined to comment on the French CJD cases, but told Science his lab never handles human or bovine prions for research purposes, only for diagnostics. “We conduct research only on mouse-adapted sheep prions, which have never been shown to be infectious to humans,” Aguzzi says. In a 2011 paper, his team reported that prions can spread through aerosols, at least in mice, which “may warrant re-thinking on prion biosafety guidelines in research and diagnostic laboratories,” they wrote. Aguzzi says he was “totally shocked” by the finding and introduced safety measures to prevent aerosol spread at his own lab, but the paper drew little attention elsewhere.
This disease was discovered due to an alert translator (most likely translating from Spanish to English) recalling that he had seen patients’ records before that had the nearly the same exact history.
After investigation, it was discovered the patients worked in a slaughterhouse near the pig brain section, where the brains were being aerosolized. Many ended up developing a progressive inflammatory neuropathy.
Keep in mind that the researcher was only 23 years old at the time when the lab accident happened. In some ways, she was basically a kid. As everyone knows, she ended up dying because of this.
A human has a fully developed adult brain around age 25, but for some people it is not until age 30 [1].
I used to mention this to my binge drinking buddies in college when they wanted me to kill more than a few brain cells with them. In general moderation in all things.
I think the point was, if you were injected with the prion in a finger, how long would you have to sever that finger to prevent the prion from entering the rest of your body.
> In a 2011 paper, his team reported that prions can spread through aerosols, at least in mice, which “may warrant re-thinking on prion biosafety guidelines in research and diagnostic laboratories,” they wrote. Aguzzi says he was “totally shocked” by the finding and introduced safety measures to prevent aerosol spread at his own lab, but the paper drew little attention elsewhere.
...
> The government inspectors' report concluded that Jaumain’s accident was not unique, however. There had been at least 17 accidents among the 100 or so scientists and technicians in France working with prions in the previous decade, five of whom stabbed or cut themselves with contaminated syringes or blades. Another technician at the same lab had a fingerprick accident with prions in 2005, but has not developed vCJD symptoms so far, Bensimhon says.
“ vCJD or “classic” CJD, which is not known to be caused by prions from animals. Classic CJD strikes an estimated one person per million. Some 80% of cases are sporadic, meaning they have no known cause, ”
Who knows really. 10 years is a long time to wait and worry, but it can take up to 50 years to express itself. Just imagine spending your whole life worrying about this.
Bear in mind that eating muscle tissue from infected animals is a much lower risk than innoculating yourself directly with brain matter from an infected animal.
The prion protein is expressed in the central nervous system, which isn't legal for human consumption. Also, ingestion of meat exposes it to stomach acid and digestive enzymes before it gets into the consumer's circulation -- enzymes that break down foreign proteins into (harmless) amino acids.
In contrast, accidentally injecting yourself with material from an infected brain is about the most direct possible infection route.
All sales of beef on the bone was banned too. Even Bovril had to change their recipe for a few years.
The ban was introduced on December 16, 1997, after government advisers reported small risks that small nerve endings near beef bones and bone marrow might be infective. The ban included cuts such rib roasts and oxtail, as well as soups and stock cubes made in Britain from beef bones.
The ban was lifted Tue 29 Nov 1999, but other bans on using as food more risky parts of cattle - brain, eyes, tonsils, spinal cord, spleen and intestines - remained in force, as did ban on use of bones in manufactured food and cattle more than 30 months old are banned from the food chain.
Things have been eased further since 1999 but I'm not sure we can get brain on the menu in the UK...
Mammalian proteins don’t differ from each other all that much so it makes sense the prions of any other mammal could potentially infect humans. Though the further away in the evolutionary tree the less likely I imagine.
Émilie Jaumain - the person refered to in your first quoted paragraph - worked at INRAE and the lab there works on prions that can infect humans. She cut her finger, and became infected.
Adriano Aguzzi's lab at the University of Zurich is the one that only works on mouse-adapted sheep prions. Presumably a similar accident wouldn't be possible there.
When lab workers studying the very thing they know best can make lethal mistakes, it's surprising that so many jumped to quell any hypothesis of a covid lab leak.
Scientists make mistakes all the time. They're human.
Imagine all of the mistakes you make in your job. Outages. Stupid bugs. It's the same with any profession.
Scientists (and logicians) avoid saying "shown to never", as it's much harder - almost impossible - to prove a negative[0]. This is also a black swan[1] type situation. The only way you can say something is never something is if you understand all occurrences of it; otherwise you can only report on what you've been shown.
Yes but the problem with "never been shown" is how it's often used to "take advantage" of people's interpretation like what you list above.
For example dropping a 27.4 kg ball on someone's head has never been shown to cause injury. We've dropped a 26.3 and a 29.5, but we've never studied dropping 27.4 kg - and as a result, "dropping a 27.4 kg ball on someone's head has never been shown to cause injury".
Frequently "never been shown" its used as a weasely way of saying "we've never looked at", or "we don't know if"
So one that is almost certain to happen given some time?
>The only way you can say something is never something is if you understand all occurrences of it;
"Understanding all occurences of it" seems like a good criterion for allowing potentially mass murderous work or not. That said, it sounds stricter than what it is. We just need them to know how a thing works and not be doing "sorcerer's apprentices" style peek and poke work.
They don't need to "prove a negative". For example we don't asks scientists to prove that "water can't explode and destroy the earth" to let them work with it casually. It's enough that they know it well. Do they know prion as well as they do water?
Yes but many experts take "never been shown to" to mean that we ought to act as if it doesn't for now. That's an important and useful social mechanism in the laborious process of constructing a solid edifice of truth from the crooked timber of humanity. But it's unwise when considering public health responses.
You're absolutely right, but it's also true that the phrase "never been shown to" most often functions in a sentence more like "doesn't/can't happen" than "we have no idea."
Yeah that’s been constant. There was ‘no evidence that delta variant is more dangerous’ for white a while, until there was actually some evidence to go on.
It seems like gain of function research is going on all over the place. Maybe Alex Jones isn't total conspiracy nut, as the media portrays him. He's just a head of what is commonly disseminated. I watched an interview with him where he claims to read a lot of research papers daily. Literally a dystopian science fiction fantasy of a virus man made in a lab infecting the world has a good likely hood of being true.
"infect" is not the right word. Prions are not viruses, they do not replicate, they ravage other proteins in their surroundings by misfolding them over and over again until it becomes a fatal pathology.
Techynically you are incorrect. Infect is the right word. Worked at the institution that established this. (I do not believe that koch's postulates cover all cases of 'infection').
The word "prion" is actually a contraction of the words "protein" and "infection". (edit: although I agree it's not what one might conventionally think of as an "infection")
A portmanteau word is similar to a contraction, but contractions are formed from words that would otherwise appear together in sequence, such as do and not to make don't, whereas a portmanteau is formed by combining two or more existing words that all relate to a single concept.
"Motel" and "fog" are portmanteaus, because you wouldn't put "motor hotel" or "smoke fog" in sentences that accept the accretions, whereas you could swap "prion" for "protein infection".
Prions are considered infectious, although when they were first proposed it was essentially heresy that something could be infectious without containing any nucleic acid (DNA/RNA).
Whether they self-replicate or not is sort of a semantic issue. They replicate in the same way "fallen-down dominos" replicate.
Prior to being a prion, they are an already complex protein, but by folding a particular way, they become a prion, which causes other proteins of the same type to fold similarly.
Infectious disease is also called transmissible diseases. Infectious microorganism or agent can be a virus, bacterium, protozoan, prion, viroid, or fungus.
Don't forget memes. Not the current pop-culture meaning of the term, but the original Dawkins version, which stretches to cover things like mass-hysteria.
I'm just saying it does reproduce (or replicate to use the exact same word op used). Whether it's correct to use any of the other terms I will leave to others
"long period of uncertainty began on 31 May 2010, when she stabbed her left thumb with a curved forceps while cleaning a cryostat—a machine that can cut tissues at very low temperatures—that she used to slice brain sections from transgenic mice infected with a sheep-adapted form of BSE. She pierced two layers of latex gloves and drew blood"
Later in the article:
""We conduct research only on mouse-adapted sheep prions, which have never been shown to be infectious to humans,” Aguzzi [neuropathologist at the University of Zurich] says."
It sounds like the assumption that mouse-adapted sheep prions can't infect humans may be flawed.