In message <[email hidden]>
Michael Hobby said:
"Peter Clinch" <[email hidden]> wrote in message
news:[email hidden]...
Quoted message said:Mark Manning wrote:
[snip]
Quoted message said:Quoted message said:I wouldn't worry. Healthy rivers are full of active biology, like
fish who excrete their body wastes into the water. People are
animals too, and if you don't spend your life sterilising
everything then you should be suitably resistant to most of the
bugs generally present in the environment.
Pete.
[snip]
Quoted message said:A little bit of dirt never hurt anybody.
The trouble with extrapolation is that you can get to proposing absurd
positions.
As an immunologist I find that the above statements have simply gone too
far.
For many people with a healthy immune system, they can tolerate exposure
to some doses of pathogens, most of the time....
However, it is not a coincidence that in those countries that have good
clean water supplies that mortality rates, particularly infant mortality
rates, are much lower.
But the immune systems of most healthy adults can also be overcome by a
big enough dose of most pathogens.
So the difficult question is knowing where to draw the line. In the case
of Pete's statement 'if you don't spend your life sterilising everything
then you should be suitably resistant to most of the bugs generally
present in the environment' I can point you to environments in parts
of the world where the whole of the local population is chronically
infected with water borne parasites and as a consequence have major
morbidity and increased mortality.
--
o/ \\ // |\ ,_ o Mike Clark
<\__,\\ // __o | \ / /\, "A mountain climbing, cycling, skiing,
"> || _`\<,_ |__\ \> | immunology lecturer, antibody engineer and
` || (_)/ (_) | \corn computer user"
