Re: Zero avian 'flu risk from wild birds


"John Morgan" <shirley.yu@xxxxxxx> wrote in message
news:444cf3f5$0$303$7a628cd7@xxxxxxxxxxxxxxxxxxxxxxxx

"BAC" <casswalk@xxxxxxxxxxxxxxxxxx> a écrit dans le message de news:
1145819666.16638.0@xxxxxxxxxxxxxxxxxxxx

"Malcolm" <Malcolm@xxxxxxxxxxxxxxxxxx> wrote in message
news:xynZMoYVt1SEFwOM@xxxxxxxxxxxxxxxxxxxxx

In article <1145788083.89829.0@xxxxxxxxxxxxxxxxxx>, BAC
<casswalk@xxxxxxxxxxxxxxxxxx> writes

"John Morgan" <shirley.yu@xxxxxxx> wrote in message
news:444b201c$0$303$7a628cd7@xxxxxxxxxxxxxxxxxxxxxxxx
The number of human cases of avian 'flu world-wide, attributable to
wild
birds, is currently put at zero. In assessing risk, this would be
the
figure, suitably scaled, that would be used to calculate human
risk.

Multiplication of the numerator of a fraction by zero does not
require
too
much knowledge of Arithmetic to work out. An 'O' grade should be
enough.



If you read through

http://www.who.int/mediacentre/factsheets/avian_influenza/en/

you will see that the main risk factor speculated on is contact with
infected birds, dead or alive. It matters not whether the infected
birds
are
'wild' or 'domestic'.

Though, as it says at the end:

"To date, human cases have been reported in six countries, most of
which
are in Asia: Cambodia, China, Indonesia, Thailand, Turkey, and Viet
Nam.
The first patients in the current outbreak, which were reported from
Viet Nam, developed symptoms in December 2003 but were not confirmed
as
H5N1 infection until 11 January 2004. Thailand reported its first
cases
on 23 January 2004. The first case in Cambodia was reported on 2
February 2005. The next country to report cases was Indonesia, which
confirmed its first infection on 21 July. China's first two cases were
reported on 16 November 2005. Confirmation of the first cases in
Turkey
came on 5 January 2006, followed by the first reported case in Iraq on
30 January 2006. All human cases have coincided with outbreaks of
highly
pathogenic H5N1 avian influenza in poultry. To date, Viet Nam has been
the most severely affected country, with more than 90 cases."

The penultimate sentence would seem to back up what John posted.


Really? Where does it say there is zero risk of contracting avian flu
from,
say, a dead (infected) wild bird?

The suggested calculation is for the risk involved, based on the current
state of knowledge. Because there are no known cases of wild-bird to human
transmission, the baseline figure for any risk calculation is that popular
oxymoron, a big fat zero.

Not at all, since the distinction you are making between 'wild' and
'domestic' fowl is arbitrary and, I think, unjustified. What is known about
those cases where humans have been known to contract HN51 (which are not
necessarily all the cases where humans have contracted it, but that's a
separate issue) is that they are believed to have contracted it from contact
with a bird or birds which were sick with the disease or which had died from
it. Hence any bird which is sick/dead from HN51 is a potential risk, if
dealt with inappropriately.

The WHO publication speculates that those who were infected were the sort of
people whose circumstances dictated they might not feel able to discard fowl
which were sick or which had died - they might well handle, pluck and clean
them and eat them. I doubt whether such people would turn up their noses at
a 'free meal' from a dead or dying wild duck which had mingled with their
stock, would you?


We can, of course, all go round wearing banana skins on our heads, as this
is known to be100% succesful in preventing malaria transmission in
temperate
and polar regions. I prefer not to, taking my chances with all the other
non-bananaskin wearers out there.



A good analogy. In your case, the 'banana skin' is the apparent belief that
the fact an infected/dead bird may be 'wild' renders it any less infectious
than if it were 'domestic'.


.