October 8th 2015 Dr.Ruth Watkins is a farmer - but also an expert virologist.
She writes today:
Prof Elizabeth Wellington's sensitive, accurate and
quantitative PCR could be a game changer if it was used to understand
the situation. I am not sure whether it is possible to do sufficient
sequencing on the PCR sample to follow individual strains by sequencing
their genes- rather as done for the outbreak of FMD in 2007 to generate
the farm sequence of infections. Whole genome sequencing is being done
in outbreaks of bacterial infection such as MRSA in a hospital to
understand the outbreak and record its source and termination. But the 2
molecular techniques could cast a powerful light.
Prof Wellington's PCR could by itself go a long way. I remember that
the CLA presentation 10 years ago at the CLA revealed that all the
badger setts were positive at Woodchester (none in the East of England
control area). That may have been why the badger ecologists would not
believe her as they were sure some setts were not infected. Also there
are areas where there are so many badger setts that the population is in
contact, and I find here that badgers are drawn to farmers fields that
are grazed short to turf up for worms, rather than stay in woodland,
even if no other incentive on the farm is provided for them (maize
fields or silage stores). There will be plenty of info on the wandering
of badgers which I think would be wide over farm fields and identifying
a single source field for a cattle herd so they could avoid it will not
be practical as badgers will not confine themselves to so small an area.
I think whole genome sequencing is so important because it could show
the flow, the order of infection. In the case of the MRSA outbreak they
would have cultured the bacteria then sequenced it. In the case of
genotyping or spoligotyping of M bovis again the organism is cultured.
However going back to sensitive quantitative PCR-
It can be used to sample latrines of badger setts in an area and
determine which are infected. It may also be possible if badgers from
the sett are caught to determine if they are infected and cull them and
culture M bovis from them to whole genome sequence the isolate. I am not
sure how it is proposed to kill all the infected badgers from an
infected sett if gassing is not allowed, but only trapping or shooting.
May be trapping, testing and culling infected badgers one by one would
over several years lead to removal of infection from that sett and the
PCR becoming negative.
This may be particularly instructive in an edge area, from within the
infected area to an as yet uninfected area (ie Leicestershire or
Oxfordshire). If there is a herd outbreak in an edge area then the
sequenced isolate can be matched with the badger setts the cattle are
exposed to in order to determine if infection is likely badger to
cattle. And vice versa if setts become infected after cattle are
If sampling was done annually it could be noted if there is spread
badger sett to badger sett so that the infection spreads outwards in an
One of the most telling uses could be to sample the latrines of badger
setts that are being vaccinated- is there any fall year to year in the
amount of M bovis in the latrines- and this sampling compared to that in
the control area.
It would be important to also study the control area as there may be an
inherent variability in the weight of infection in setts from year to
year without any interference of any kind.
In the IAA in Pembrokeshire it could perhaps be done next year in the
5th year of the vaccination and compared to the control area and be done
again the year after vaccination has ceased.
I am not sure about its use on farm. One could get into difficult
situations such as a farm positive by skin testing but negative by PCR
on slurry or milk and vice versa. I am not sure the tests on cattle are
sufficiently good to sort this out. DEFRA do not resolve the issue in
instances where large numbers of cattle test positive on the bovigam
test but have no other test positive nor sign of TB as in the Saunders
of Oxfordshire case.
The milk tank testing might be useful as it is relatively sterile and
emptied and refilled daily or every other day. Any organism in slurry
could be likely to be around for at least 6 months after infected cattle
are culled and may have been introduced by a passing badger. I would
think the amount of organism in milk is likely to be greater and appear
in more infected cattle than shedding in urine or faeces which I believe
would occur later. Perhaps checking the milk tank on infected dairy
farms may prove to be useful.
This is all quite intensive and expensive but could contribute to
understanding the cycles of infection in cattle and badgers and their
significance, and contribute to examining the effect of BCG vaccination
of badgers. As you know the CVO of Wales has announced that the 5 years
of special on farm measures taken in the Pembrokeshire IAA and the
vaccination of the badgers for 3 years in the IAA to date have made no
difference to the incidence of herd TB inside the area. It is no
different from that in the control areas."
September 7th 2015 ~ A way to bring the opposing sides together - but DEFRA's silence continues
It provides a pretty much foolproof way of identifying infected wildlife, and especially badger setts. Using non-invasive PCR to check for the bacterium
in badger droppings in
the vicinity of a sett means no need to trap, no need to stress the animals - and above all, no need for the random killing of
badgers in the cull areas.
We are not alone in wondering why on earth there has been so very little reaction to the Warwick Research, led by Professor
Liz Wellington, painstakingly carried out over ten years, paid for largely with taxpayers' money, and brought to an extraordinarily successful conclusion.
The research and details of the tests were publicised in July.
It is now September.
Perhaps a clue for DEFRA's reluctance to get moving comes from the latest
It points out that
"...if Defra used the research - into the identification of infected setts, for which the taxpayer has paid,
then all of this long running farce would have to stop. And it would, as once an infected area and group of animals is identified,
by international statute,
Defra have to act on that information. They have no choice."
In other words, the Department would be in inescapable legal trouble if they failed to act, once infection was known to be present.
At present, all responsibility, and indeed blame, can be laid at the door of farmers themselves for what the public is encouraged to think of as poor "biosecurity".
Farmers Guardian Insight reports on the continuing exodus of working farmers in Britain. At a time when many parts of the
country produce little more than
financial services and the growth of debt, this may be thought disastrous.
August 28th 2015 ~ DEFRA News Release today: "New proposals to protect livestock from bovine TB" - but DEFRA silence continues on camelids and on newly developed tests
The news release may be seen in full
It says: "As part of our measured approach to tackling bovine TB and achieving disease control benefits Natural England
has authorised targeted badger culls in Gloucestershire, Somerset and Dorset this year." No mention at all is made of the possibility of
making use of the new, successful and non-invasive PCR tests to identify infected badger setts
- the work developed by Professor Wellington at Warwick University and funded by DEFRA itself - a breakthrough
that could surely bring both sides in this long-running and distressing debate together.
The proposals today are
Introducing compulsory testing for all cattle entering low-risk areas, such as the north and east of England
Changes to the criteria for future badger control licences such as reducing the minimum area for a licence
Controlling TB in non-bovine animals such as pigs, goats, and deer. (No specific mention of alpaca herds)
Pointed out many times on this website is the fact that alpacas are particularly susceptible to the disease.
FGInsight fact sheet points out:
"Once a bovine is infected it does not immediately start spreading the disease.
TB develops very slowly and it takes time for lesions to grow in the lungs –
and these lesions have to open up before cattle start coughing out the bacteria."
Unlike cows however, camelids spread the disease quickly to those with whom they come into contact. Unlike cattle,
alpacas die very quickly
when they contract bTB.
Alpacas often move around the country in order for mating to take place. Yet testing STILL remains voluntary.
The multi-antigen Enferplex assay for bTB whose advent was greeted over a year ago.
was developed by the Dorset-based 'SureFarm'
veterinary group after llama and alpaca owners approached them for help. The test is said to
work well for llamas and alpacas, but in addition to camelids, could be used equally well for cattle, goats, pigs and wild boar,
deer and badgers.
August 27th 2015 ~ Virologist Dr Ruth Watkins: "I am so glad that Prof Wellington has been working with DEFRA to do this qPCR work and
I highly commend her for it."
Dr Watkins' email can be seen here. She recalls, at a CLA meeting a decade ago, "how unbelieving and
dismissive the badger ecologists at Woodchester had been to Professor Wellington's work. As a virologist, Ruth Watkins raises
aspects of the work that she feels are important both from the point of view of a farmer and as a microbiologist.
August 26th 2015 ~ BBC Farming Today and the new "game-changer" Badger Test. "It really is a major breakthough in terms of tackling the disease,"
says Professor Wellington
Listen here (about 8.40 minutes into the programme)
The Farming Today programme interviewed Professor Liz Wellington yesterday.
"After more than a decade of work, scientists have developed
a test which they say could be a game-changer....the PCR test can detect whether badgers using a particular sett are infected with bTB
and, crucually, spreading or shedding the disease. The research is also underway to establish whether the test
could be used to map the disease in cattle through screening of slurry or even milk. Professor Elizabeth Wellington
at the university of Warwick led the research to develop the PCR test for badger setts. She explained why she believes
the test on badger faeces is a significant step forward.
August 26th 2015 ~ Partial transcript of Farming Today's interview with Professor Wellington
"It's more sensitive than previous tests and it's non invasive...you don't need to trap
the badgers and take blood from them and disturb them. It's also better because it
measures a much greater level of the population
because we measure infection in a lot of faeces in a latrine. And you
can also look at contamination of pasture, contamination of food supplies, contamination
the whole farm where the setts are established." Asked whether the test could
be used as an alternative to culling, targetting just the infected setts, Prof Wellington explained:
"The way in which we control the disease and prevent the spread is
a question of integrating all the methods of establishing bTB-free herds." It is not any question of lack of accuracy
" it's to do with the impact on movements,
because you get a lot of badger movement, so the way we regard it is that farmers
can improve their bio-security, they can establish if they have contaminated pastures and they can establish which setts
are shedding on their land." Farmers, she said, could move cattle away from
infected pasture. "We consider very important the environment as a route of
transmission. Because at the moment, nobody has really done a full-scale monitor of infection
across the main areas - South West and Wales - we could do this.
This test, if it's done in a high through-put way
is relatively cheap."
Prof Wellington said that her results were good enough
to counter any criticism
that PCR hasn't in the past been "reliable enough" in the field.
"We've done a number of validations, both across Europe in different labs and within the UK
and we've now published all that data. It's freely available for everyone to read."
August 26th 2015 ~ Will DEFRA use the new test? Farming Today. "..it's something we need to put into action as quickly as we can"
When asked whether DEFRA, after having funded the research, had "committed" or "given any indication" of whether it will be using this test, Professor
Wellington replied that she was "not aware of anything at the moment". She agreed that the silence from DEFRA was
frustrating for the team and for
both wildlife enthusiasts and farmers. Anna Hill pointed out that the disease costs the country
"hundreds of millions of pounds over the years" Professor Wellington replied that her team and many other people
believe that the new test
is a major breakthrough in terms of tackling the disease...
we can map out, throughout the season, shedding in both cattle and badgers.
So I really think it's something we need to put into action as quickly as we can"
Anna Hill then reported that DEFRA had told Farming Today that they were "assessing the study" before
deciding what action to take. One can only hope the assessors are able fully to appreciate the importance
of this ten-year study. (
Listen here about 8.40 minutes into the programme)
August 23rd 2015 ~ Farmers in hotspots "attempt to comply with some of the most ridiculous and imaginative obstacles" -
and yet a highly effective test exists...
...to identify bTB infected badger setts.
So why the continuing silence on PCR? Its method allows M. bovis infections in badger populations to be monitored
without trapping and provides additional information on the quantities of bacterial DNA shed.
The latest posting from the bovinetb.blogspot.co.uk
shows how very mistaken were those who poured doubt on a project "commissioned by Defra, paid for by us, the taxpayer" which
"met with a deafening silence"...ie Professor Wellington's paper on PCR (pdf)
which has now been published in full in the Journal of Clinical Microbiology, July 2015. Its conclusion, explains the post, describes a
" non invasive field test,
offering 100 per cent sensitivity using latrine fecal samples taken in the summer,
with which to identify those badger groups causing most of the upspill into other mammals, farmed or companions.
A targeted management strategy.
The cost, Prof. Wellington puts at around £200 per sett tested (20 samples)"