In article ,
Janet Baraclough.. wrote:
The message
from (Bill Oliver) contains these words:


In fact, a 1996 estimate is a good place to start, since
the risk has gone down since then.

The risk of eating BSE-infected beef in Britain, has gone down since
then. That is not the same as saying, that the incidence of nv CJD
infection will decrease, because a) virtually all the meat-eating
population of the UK was exposed to BSE for at least a decade and B) we
still don't know the incubation period, or what other factors activate a
dormant infection.


But you do know the prevalance of symptomatic disease, and that
is decreasing. You also know a good deal about conventional
CJD and you know that the route of transmission and pertinent
vectors are essentially the same. In order for the hysterical
view to be correct, you would not only have to posit not
only that "we still don't know the incubation period" but
*also* that this unknown incubation period is actively
*increasing* in order to explain the decrease in the
symptomatic cohort. Otherwise, a constant percentage
of infected people would become symptomatic. Since
fewer people are becoming symptomatic, either the
number of infections is decreasing or the incubation
period is magically increasing.

You know that the exposure is decreasing, the prevalence
of symptomatic disease is decreasing, you know that there
is no evidence of significant other methods of transmission,
and you have no rational reason to believe that the decrease
in symptomatic patients is because there is a large reservoir
of disease that is busily increasing its dormancy period simply
to stay hidden.

Unless you believe in magic the risk is decreasing, and the
1996 calculations provide an upper bound.



You're conflating statistics. There are only 15 *known* nv-CJD
infected human blood donors; their blood never reached "millions and
millions" of recipients. One case of infection from only 15 donors is
rather more worrying.


Well, no. I entered this because a respondent used the ban
on donors as evidence of risk. It is not. And the millions
and millions of recipients apply to that. Further, your
claim provides its own problem. There were only 15 known
vCJD donors in this study. Are you now positing that
there are not many, many untested prion-positive donors?
In fact, and if you really want, I can provide you with
articles that provide good evidence that *lots* of
people with prions have given blood. Where are *those*
cases of vCJD?


The "decade ago", is not yet grounds for complacency either, since we
still don't know the full range of the incubation period. Recent
research on discarded appendixes and tonsils showed that some of the UK
population are still carrying the prions.

Right. And you posit that this incubation period is *increasing* because
those clever prions just don't want to get caught. That's why
the number of patients with disease is decreasing, right?

billo