Back
to ANIMAL HEALTH - GENERAL - Homepage
Further comments on diagnostic testing for
Avian Flu and other diseases of livestock
Letter to the editor from
Roger Breeze
CEO Centaur Science Group, a science consulting
forum,
Washington DC, USA
Formerly Director, Plum Island USA Department of Agriculture
Filed 12 Apr 06
©www.land-care.org.uk
Dear Dr Irvine,
The rapid PCR tests that USDA invented
for FMD, classical swine fever, avian influenza, Newcastle disease
and others in 2000-2001 are single tests - they were designed
to test one animal sample for one pathogen at a time. Almost unbelievably,
five years later, these single tests are not yet formally recognized
as the benchmarks for disease diagnosis by veterinary regulatory
authorities in North America, Europe and the International
Office of Epizootics. And the significance of the fact that
the foot and mouth and classical swine fever tests will find infected
animals 2 to 3 days before they show clinical signs of disease seems
to have escaped most animal disease control agencies.
I recently proposed in this forum (1)
that Scotland should invest in 9 or 10 RAPID PCR machines for
avian influenza and other foreign animal and poultry disease detection
at regional labs. This machine can test over 30 samples at a time
for the same disease or for several diseases using the single PCR
tests. It was not my intention to suggest that this should be the
only national investment to drive detection and diagnosis closer
to the point of need on the farm: the March of Technology is inexorable
and we are about to see waves of new devices and test technologies
come onto the commercial market (although not the market for critical
diagnosis of the world's most dangerous livestock diseases, which
is satisfied with the technology of our grandfathers).
Specifically, I must draw attention to
the imminent availability (2006) of a test cassette format (the
machine has been on the market for some time) that will allow a
sample from a single animal to be tested by real time PCR for up
to 12 disease pathogens simultaneously in about 20 minutes (this
is known as multiplex testing). This machine is about the size of
a small loaf of bread and operates when slung over the shoulder
or in a moving vehicle. It is ideally suited for investigative use
on farm or at the site of the dead swan. The PCR tests, cassette
format and device are state of the art for the U.S. military on
land, sea or air, or underwater. Later this year, a further investment
of about 300,000 pounds would provide this mobile detection capability
via staff of the 9 veterinary investigation labs for on-farm diagnosis
throughout Scotland. One might choose a standard test cassette
that detects the 12 most important foreign livestock and poultry
diseases threatening the UK or species-specific cassettes that
detect the 12 most important infections, foreign and domestic, of
swine, poultry, etc.
What's alarming about failure to deploy
rapid PCR tests even to regional diagnostic labs since 2001 is that
technology has moved on significantly while nothing was being done.
The means to detect on the farm has got even better since 2001 -
it did not disappear just because responsible officials had their
heads in the sand hoping it would go away. We cannot afford to find
ourselves in 2012 still waiting for officialdom to formally approve
the technology I just described above. Just remember when you hear
scientific experts telling you that it is not possible to detect
avian influenza with real time PCR in the regional Scottish diagnostic
labs today that the next generation of on farm test capability is
now coming to market (you will be able to buy it to detect the most
dangerous viral and bacterial biological weapons threats to people
in Autumn 2006, including avian influenza H5N1) and the generation
beyond that is emerging from research laboratories.
Finally, let me apologize to the staff of the 8 SAC regional veterinary
diagnostic centers. I have been gone from Scotland almost 30 years
and didn't know where the regional vet labs were located but
my proposed locations were not far from the mark. Of course, as
a Glasgow graduate (2) I naturally assumed that
the mother city would be the epicenter.
Best Wishes,
Roger Breeze
Email: breezerg@verizon.net
Mobile: (USA) 202 841 1555
©www.land-care.org.uk
References
1. Breeze, Roger (2006). The management
of Avian Flu H5N1. If not us, who? If not now, when?
See ANIMAL HEALTH - GENERAL - Homepage, filed 07 Apr 06,
www.land-care.org.uk Click
Here to View
2. Roger Breeze got his
veterinary degree in 1968 and his PhD in 1973 from Glasgow University,
Scotland. He taught in veterinary pathology at Glasgow from 1968
to 1977.
|
