BSE versus Creutzveld-Jacobs-syndrome

[Nigel Smith]

In article <4jhafv$1dpq at pegasus.unm.edu>, bhjelle at unm.edu wrote:

> I would make a huge contrast between the high voltage
> wire-cancer link and the risk of cross-species transmission
> of BSE. In the laboratory, BSE has been transmitted to mice,
> goats and sheep via the oral route (see http://www.airtime.
> co.uk/bse/tse.htm.#immunity). BSE can be transmitted into
> transgenic mice bearing human PrP and produces human PrPSc.

Well, from that link:

> Immunity

> Developed immunity against the infective agent has not been
> demonstrated. Apparently no antibodies that react with it are
> produced, even in chronically infected animals. The possibility
> that this may permit multiple inoculations of sublethal doses
> of the agent to be effectively additive in their effect has
> been considered and is presumed by some researchers but no
> specific proof of this has been shown. Rabbits may produced
> antibodies against PrP derived from sheep (vide infra).

So, not a mention of an oral route there, then.
IIRC, the *test* for BSE requires direct injection into a mouse, since the
is no contagion via the oral route.

> As for the risk from sheep and pigs, I would say that if
> we had 160,000 cases of scrapie in sheep or porcine
> spongiform encephalopathy, it should be regarded with the
> same concern as the bovine epidemic.

Scrapie has been endemic in sheep around the world for more than 200
years. I would be *very* surprised if there hadn't been 160,000 cases by
now.
 
> I would challenge you to convince me that the operation of
> slaughterhouses could be modified to prevent low-level
> contamination of meat with neural tissue, and still have
> an economically viable operation.

And I challenge you to find any record of any contamination in meat for
sale. There has not been a single case where joint of beef has been found
to contain the prions believed to be the agent of transmission.

      Nigel