Back
to ANIMAL HEALTH - GENERAL - Homepage
Serious concerns about how DEFRA organised
the collection of samples for Avian Flu testing
James Irvine
Teviot Scientific, Edinburgh and Perthshire
Filed 14 Apr 06
©www.land-care.org.uk
A basic principle in any laboratory diagnostic
procedure is to ensure that the samples to be tested have been collected
properly. This is to ensure that the pathogen in question is not
lost or destroyed between the time of taking the sample and the
actual testing procedure in a laboratory.
Strange to tell but all may not have been well
with regard to the advice that Defra allegedly gave to the conservation
bodies and others with regard to how samples were to be processed
as part of Defra's survey of wild birds - more than 3500 of them
- for Avian Flu. It now transpires that the boast by the UK Government
Chief Scientist, Professor Sir David King, that all wild birds tested
so far were negative for H5N1, might have been ill-founded. Perhaps
if he had had some grounding in biology, rather than physical chemistry,
he may have been in a better position to seek reassurance that the
tests were being done properly at the most basic level - sample
collection.
It would appear that we in the UK owe it to the
Swedes and to the Americans for pointing out that there was something
wrong with the UK findings. There are a number of different strains
of Avian Flu with some of them being relatively benign, such that
some 6 - 10% of certain species of water birds in the wild would
be expected to carry them. Defra's recent figures claimed that only
some 0.07% of UK's water birds of the same species did so. Is it
that the UK's waders are much more healthy than those of other countries
(in spite of the fact that many are migratory), or is there something
wrong with the way the UK have been doing their tests?
In a well researched article in New Scientist,
Debora MacKenzie (1) appears to have found the
likely explanation. Crucial to the issue is how the samples from
the birds were sourced and subsequently handled. She reports that
Defra instructed the Wildfowl and Wetlands Trust (WWT):
"to moisten a sterile swab on a stick with
saline, take a faecal sample from the bird, then put the swab
back in its dry plastic tube. The tubes were then kept at refrigerator
temperature and taken to the testing laboratories the next day."
The trouble with this is that the sample under
these circumstances would dry out and any virus present would be
lost. That is the firm view of Bjorn Olsen, University of Kalmar,
Sweden who tests up to 10,000 wild birds per year in Europe's biggest
monitoring programme for avian flu. It is also the stated view of
Jacqueline Nolting, Chief Technician to Richard Siemmons, Ohio State
University of Columbus who has tested 2000 to 3000 water birds per
year for 20 years.
It is alleged that Defra, who have never done
large-scale surveys before, failed to take advice from those who
have.
The New Scientist Report ends with the depressing
message from Professor Olsen:
"H5N1 was most likely carried to the UK
by migratory ducks, which could have spread the virus to wintering
grounds all over the country. Defra's tests would probably not
have picked it up"
Meanwhile Defra claims the single swan with H5N1,
washed up dead on the shores of the East Neuk of Fife, Scotland,
was a whooper swan that had probably migrated from elsewhere, explaining
why all Defra's tests in the UK's wild birds were negative.
Deborah MacKenzie's New Scientist Report further
undermines confidence in the competence of Defra to handle matters
regarding the management of infectious diseases of livestock, let
alone other areas where Defra's incompetence is all too manifest.
On this occasion there are very serious allegations over the neglect
of fundamental principles regarding the collection of samples.
Previously, it was the inappropriate mixing of
samples from birds in quarantine from different countries. One of
the birds proved positive for H5N1, but which one and from what
country? And of course there was the notorious mixing of cattle
and sheep brains when "research" was being carried out
on BSE and scrapie under its auspices. Also, Defra seems to have
some strange ideas as to how immunology works. As farmers in England
know to their severe cost, Defra seems unable to administer its
chosen Single Farm Payment scheme, leading to crippling cashflow
problems.
Somebody needs to get a grip on Defra before it
commits any more highly dangerous and embarrassing catastrophies
that can threaten the health of people as well as livestock and
are potentially financially ruinous. But that is what comes of being
overzealous about `'the environment`', and not paying attention
to the basic principles of livestock management It is about time
that the word "Agriculture" got back into the name of
the department that is currently called Defra (Department of Food
and Rural Affairs). And it is certainly time Westminster got a new
Minister for said department. A new Chief Scientist would also help.
But if Tony Blair is not willing to oust his cronies, then a crash
course for Defra employees from the top down on basic virology and
immunology would be in order.
When contemplating controlling epidemics, or carrying
out surveys in relation to the spread of infectious diseases, Defra
would do well to seek advice from others with much greater experience
in a specific field. But they should also draw on the vast experience
within the National Health Service that exists on their own doorstep.
Virologists within the NHS would certainly know how to collect samples
properly. I am sure they would have been happy to spare the few
minutes to pass on the know-how to Defra.
But perhaps NHS virologists and clinical
epidemiologists should have a permanent monitoring role on the activities
of Defra. If nothing else that should ensure that Defra complies
with the relevant standards that all NHS laboratories are familiar
with.and which come under the heading of Quality Assurance - a concept
ironically that is no stranger to UK farmers.
©www.land-care.org.uk
References
1. MacKenzie, Debora (2006). UK's
bird tests may be missing flu virus.
New Scientist, 15th April, 2006. Magazine issue 2547.
www.newscientist.com
Finis
|
