[912] in Vegetarian_Support_Group
RE: BSE
daemon@ATHENA.MIT.EDU (Lewis Haddow)
Wed Apr 10 09:31:12 1996
From: "Lewis Haddow" <9235367@arran.sms.ed.ac.uk>
To: vsg@MIT.EDU, Charlie Behrens <CHARLIE@aimtech.com>
Date: Wed, 10 Apr 1996 14:30:33 +0000
> Date: Tue, 9 Apr 1996 08:20:00 +0000
> From: Charlie Behrens <CHARLIE@aimtech.com>
> Subject: RE: BSE
> To: Raymond Q Luk <rql@MIT.EDU>, vsg <vsg@MIT.EDU>
>
> You raise excellent questions. Especially, "How long have sheep been known
> to have scrapie?"
>
> It seems only logical to me that since sheep scrapie is the source of BSE,
> eating infected sheep could very well be deadly to humans too. However, as
> prions migrate to cows, humans, and other animals, my understanding is that
> they manifest different symptoms, not necessarily as deadly as BSE, or
> perhaps even worse. Whatever the specifics though, I have little doubt that
> eating scrapie-infected sheep is bad for humans and should be avoided.
> ----------
I'd like to answer this question with what I learnt in Neuroscience
in Edinburgh a year ago. Scrapie has been around for a *long* time.
Even the name sounds pre-industrial. It was only in the latter part
of this century that a bright vet noticed the similarity between
scrapie, CJD and Kuru (a disease of cannibals); subsequently BSE and
loads more have been added to this list. As you know, BSE appeared
through the chance mutation of the Scrapie agent (a prion? - who
knows?) in cattle feed. This mutation happened once only, in the
south of England, hence there is only one strain of BSE, while there
are loads of strains of Scrapie (more evidence of its ancient
origins).
There is no evidence that scrapie can be passed to humans.
Cultures where lamb and mutton are popular (eg north Africa), where
they even eat sheep's eyes, have no higher level of spongiform brain
disease. Australia, where sheep greatly outnumber humans, is the
same. Shepherds and sheep-shearers are no more likely to suffer from
Prion diseases than the general population.
But this is the interesting part: scrapie cannot be given to cats,
however much sheep brain they are fed. However if you give the
disease first to goats, then cats can contract Feline Spongiform
Encephalopathy from the goats' offal. So there is evidence that
prion diseases change their species-specificity in a curious way with
each jump of a species barrier. Hence the fear of the BSE prion
being altered to affect humans.
The moral of the story is, don't eat other animals unless you're a
carnivore!
Yours
LH
