wrote:
In article ,
Jeff Layman wrote:

To twist the original thread name, your reply is bullshit. "Horribly
plausible"? To consider what might occur there is Definite, Probable,
Possible, and Plausible. It was plausible that the earth was flat until
proved otherwise. I suppose it was plausible that the moon was made of
green cheese before the facts were examined carefully.

I am afraid that it is YOU who are bullshitting! Let me remind you
of the facts when the news first broke:

1) There was a scrapie-like disease that was MUCH more aggressive,
was widespread in cattle and had been seen in humans.

I assume you are referring to nvCJD. Yes, BSE was much more aggressive in
cattle, but by putting that phrase "and had been seen in humans" in the same
sentence you are drawing an unsubstantiated conclusion that the disease is
much more aggressive in humans. Even if the BSE prion and nvCJD prion are
the same (I have not checked this) can the conclusion be drawn that they
behave identically in cattle and humans?


2) This was believed to be a variant of scrapie that had crossed
the species boundary and mutated, due to the practice of feeding
processed sheep offal to cattle.

3) The agent was known to be unaffected by cooking.

4) It was known to be mainly in the central nervous system, but
there was good evidence that it also occurred in musculature and in
milk.

5) We didn't have a clue what proportion of the UK cattle herd
was infected, and educated guesses ranged from 0.1% to 99%.

How can you use the term "educated guess" and "ranged from 0.1% to 99%"?
Why is a smiley missing from the end of that sentence?

6) We didn't have a clue of how infectious it was, or how soon
after infection it could be transmitted, either in cattle or humans.

7) We didn't have a clue about how long its symptoms took to
develop, except that it was not a matter of months.

8) We had no test except an autopsy, and even that was very
unreliable except in advanced cases.

So why draw only the worst conclusions? It's like multiplying all degrees
of error together to come up with the worst possible outcome.


The nightmare scenario was that it was highly infectious, but very
slow developing. If that were the case, 99% of the UK cattle herd
could have been infected, possibly 70% of the UK human population,
but the symptoms wouldn't peak in the latter for 2-3 decades.

No, even though it was highly infectious in cattle, nothingcould be
concluded about its infectivity in humans. And based on the lack of
transmission of scrapie to humans, despite sheep brains being on the menu
for years, why draw the unobvious conclusion about the BSE agent? Or are
you making a kuru comparison? If so why the latter and not the former?


The optimal scenario was that it wasn't very infectious at all, and a
large proportion of infected subjects showed symptoms within a couple
of years. There was ABSOLUTELY NOTHING to distinguish this one in
plausibility from the nightmare scenario.

Sorry, I don't understand what you are saying here. If a large proportion
of infected subjects showed symptoms within a couple of years, isn't that a
nightmare scenario - early onset disease and no cure? Delay for 30+ years
might mean a cure being found in the interim.


The government was attempting to ignore the problem, and to carry
on, but the experts used the the press-induced hysteria to force it
to (a) stop feeding ruminant protein to ruminants and (b) investigate
vCJD as a matter of urgency. They were right to do so.

Here we are in agreement. But I am not sure if the Government was acting
only in what they do well at - ignorance - rather than being totally malign.


What evidence do YOU have that the optimal scenario (which seems to
be the case) could have been determined to be more plausible than
the nightmare one USING ONLY INFORMATION AVAILABLE AT THE TIME.

I no longer have access to the original papers, but this is from a review
paper by Peter Campbell on BSE/MCD (Med Principles Pract 1998;7:172-186).
It is thus only a couple of years on from the original papers on the
subject.
(http://content.karger.com/ProdukteDB...rtikelNr=26039)

"In view of the long incubation period of 5-10 years for nvCJD, based
largely on the assumption that the greatest chance of people eating infected
beef was between 1980 and 1988 when the ban on MBM was instituted, no sound
estimate could be given of the likely scale of the epidemic of nvCJD, but
the possibility was mentioned that it could run into thousands of cases.
Fortunately, so far the worst predictions have not been fulfilled since the
number of new cases is about 1 per month with a total to date of 23."

Note: "...no sound estimate could be given of the likely scale of the
epidemic of nvCJD, but the possibility was mentioned that it could run into
thousands of cases...". So here, only a couple of years on from the
original publications, we have a reviewer noting the connection between "no
sound estimate" and that the "worst predictions have not been fulfilled".
So why was an "epidemic" and "thousands of cases" mentioned when it was not
possible to give a sound estimate? Because the "worst possible scenario"
sells papers. And of course the journal paper gets referenced many times
(useful if you are after a DSc. of course). That's the point I am trying to
make. Yes, based on the worst possible case we could all be mad and/or dead
now. But previous experience (The Plague, Spanish flu, HIV/AIDS) shows that
the worst possible scenario just doesn't happen. And that's when we have
good information about a disease - not surmise upon surmise. It wasn't
science as it should be, carefully peer reviewed; it was "jump on the
bandwagon" stuff.

At the time, one scientist, Professor Richard Lacey, was quoted as saying
that "due to BSE, in the years to come our hospitals will be filled with
thousands of people going slowly and painfully mad before dying". So what
new evidence did Lacey have that the Southwood Report did not have only a
year earlier? The Southwood Report may have been derided for its comment
that the risk to human health (from BSE) was remote, but the report did
include certain caveats as to the risk to humans if certain assumptions were
to be proven incorrect. What's Lacey's excuse, or was he quoted
incorrectly? Where are these thousands of people going mad and dying?


I suggest you go back and read some of the "scientific" comments made at
the time. I had access to all the main medical and general (such as
"Nature") journals at the time (1996) and could not believe what I was
reading in them. I was ashamed to be called a scientist. ...

I did. I also extracted the information from them and did my own
analysis. Nature's statistical quality is traditionally awful, so
I obviously didn't rely on any conclusions published there.

I can't comment on Nature's statistical quality, but obviously someone
believed them. And what did your analyses show? If based on the sort of
information you alluded to in point 4 above, was there any point in doing
them?

Regards,
Nick Maclaren.

--
Jeff