R.Burge at bay.cc.kcl.ac.uk
Fri Apr 29 10:59:24 EST 1994
In article <1994Apr22.151719.55745 at ucl.ac.uk> spbcnsp at ucl.ac.uk (Mr Neville Steven Percy) writes:
>Well I meant it had never been known to cross the sp. barrier:
What I meant was that Scrapie has been around since the year dot, yet there
has been an explosion of prion diseases discovered in other species relatively
recently. I couldn't begin to give you epidemiology statistics for the spread
of these diseases as it is way, way outside my field, but my gut feeling is
that there *must* be cross species transmission or else some environmental
factor has sprung up this century which induces this sort of mutation (prp-c
-> prp-sc like protein).
The other explanation of course, is that until relatively recently, we haven't
had things like a pet-food and animal-food industry to steam reclaim the dodgy
bits from infected carcasses, which is why Scrapie didn't appear to cross the
species barrier for so long - cows weren't eating sheep brain.
>TME (Transmissible Mink Enc.) and FSE (Feline Spong. Enc.) both date from
>after the outbreak of BSE, rather than having ever been arisen from
>Scrapie infected sheep. Likewise all the exotic antelope diseases in
>Kudu and Oryx and things.
Correct me if I'm wrong, but haven't these only been found in Zoo animals
which have previously been fed on the same sort of animal feed that has been
suspected of contamination, i.e. the Oryx have probably been eating Cow/Sheep
offal in their feed.
Richard Burge | e-mail:
King's College London | R.Burge at bay.cc.kcl.ac.uk
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