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So Avian Flu H5 has arrived in GB.
But how is it being handled?
James Irvine
Teviot Scientific, Edinburgh and Perthshire
Filed 06 Apr 06
©www.land-care.org.uk
The sequence of events so far appears to be as follows.
On Wednesday 29th March 2006 a member of the public,
Tina Briscoe, came across a dead swan washed up on the shore at
Cellardyke, a small coastal village in the East Neuk of Fife, Scotland.
Fortunately she knew a researcher, Dan Young who worked at the University
of St Andrews, who came to see the swan and reported the finding
to DEFRA. He stated on TV that he thought that the dead swan may
have been there for some days.
DEFRA sent someone to examine the dead swan and
collected it about 12 noon the next day. Ms Briscoe was concerned
at the delay before the bird was picked up, leaving the opportunity
for cats and other birds to pick at the carcass. Cats in other countries
- notably Germany - have been known to die after eating the flesh
of H5N1 infected birds.
The specimen (the dead swan) was sent to the relevant
laboratory (was it Weybridge?) the day after, but the laboratory
was closed for the weekend. So testing could only have begun on
Monday 3rd April at the earliest.
The positive finding of an H5 strain of Avian
Influenza virus from samples taken from the swan was established
in the afternoon of Wednesday 5th April: that is, a week after the
dead bird was reported to DEFRA.
The reassurance from Charles Milne, the
Chief Veterinary Officer for Scotland, that he was happy with the
time scale, and that everything was being done that could be done,
is disappointing because it appears to lack credibility.
Comment
In the management of a potential outbreak of a
highly infectious disease of livestock - be it Foot and Mouth (FMD),
Classical Swine Fever (CSF) or Avian Influenza (AI) - time is of
the essence. Although the laboratory involved may have tested a
large number of birds to date in their surveillance programme, there
would seem to be little excuse for taking a week to come up with
a result, as the imminent threat of Avian Flu reaching the shores
of Great Britain has been obvious for a considerable period of time.
It asks the same question as previously asked
in relation to the FMD UK 2001 outbreak - do we have laboratory
resources that can cope with the number of samples? Why was the
key laboratory closed for the weekend at a time of supposedly heightened
surveillance? The laboratory which is involved in establishing whether
or not it is an H5N1 strain that is implicated would be Pirbright,
which is based in Surrey in the south of England. What is not clear
is how many different laboratories the samples need to go to in
the process of being tested. As of 1.45pm Thursday 6th April there
has been no official announcement as to whether the strain of virus
found in the dead swan on 29th March is H5N1 or not.
The authorities and everybody else may be lucky
that the virus may not have spread locally in the intervening week,
and they may even be very lucky that the strain of H5 may not turn
out to be of the N1 variety. But we should not be depending on luck.
What is worrying is that the dead swan found at Callerdyke was a
mute swan - native to Scotland and not one that has migrated from
another country. So where did this swan get the virus from? What
else is lurking out there?
Speed and reliability of diagnostic tests
The sequence of events as described above
reveals that modern technology is still not being used, again suggesting
that there has been little progress in this area since the inquiries
into what happened with the disastrous FMD UK2001 epidemic. What
has happened to the recommended rapid task force that would go to
an area where disease is suspected, armed with portable RealTime-PCR
equipment that could make a reliable diagnosis, including strain
type, within 4 hours maximum?
Movement restrictions
An exclusion zone with restrictions on the movement
of poultry within a 3km radius zone, and surveillance zone over
a 10 km radius from where the diseased swan was found, were established
once the virus had been established as belonging to the H group
of Avian Flu viruses. Again luckily, there are no known commercial
poultry farms within the exclusion zone, although there are three
commercial poultry farms within the surveillance zone, one of them
large. There is a very large commercial poultry enterprise not so
many miles away near West Linton.
The UK government was very late in establishing
a register of poultry farms. The closing date was 28th February
2006. but this only covered enterprises that had 50 or more birds.
The authorities are now trying to establish who else has poultry,
including within the exclusion and surveillance zones. This can
hardly be called appropriate preparedness for a danger that has
been known to be imminent for a considerable period of time - the
current global spread started in Asia in 2003 and has been relentlessly
coming our way ever since.
Whether or not to vaccinate
The folly of the UK government's stance on vaccination
of poultry against the H5N1 strain of Avian Influenza is now becoming
all too apparent.
It does take some 3 weeks for maximum protection
to be achieved using two doses of currently available vaccine (Intervet
Nobilis). But the availability depends on when it was ordered. Free
range birds could have been vaccinated so that they did not need
to be housed should there be an outbreak. What is apparently not
sufficiently recognised is that free range enterprises have housing
that is appropriate for free range birds that only require to come
under cover for laying their eggs and not continuously. There are
serious welfare problems if free range birds are housed continuously
for long periods.
The UK government has ordered (but probably not
yet received) 2.3 million doses of H5N2 vaccine (Nobilis) for use
in zoos and rare breeds. It has not ordered any for commercial poultry,
and according to announcements on TV today "has no intention
of doing so".
Such a policy is at variance with the policy adopted
by the French and by the Dutch., who are already vaccinating poultry.
The policy is also at variance with the opinion of the UK's leading
virologist on the subject, Professor John Oxford of London.His opinion
was casually dismissed by Government Minster Ben Bradshaw on a recent
TV programme as "just one opinion among many".
Viruses are no respectors of the boundaries of
EU member states or non-member states, or anywhere else. It is a
pity that the UK government chooses to take such a negative approach
to the benefits of vaccination compared to the French and the Dutch.
It may well rue the day that it decided to stick by old thinking
and old habits and not take advantage of new technologies.
It is to be hoped that the diagnostic process
can be somewhat more prompt in relation to the two dead swans found
today in Richmond Park, Glasgow. Apparently samples have gone off
to an SAC laboratory. Better hurry, because the weekend will be
coming up shortly.
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