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‘False positives’ must be eliminated

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New bovine TB tests needed?: Cambridge University has recommended

New bovine TB tests needed?: Cambridge University has recommended

A NEW study performed by researchers from Cambridge University has recommended that new tests are needed to make vaccination against bovine tuberculosis (bovine TB). The report points out that in order for vaccination to be viable, the number of false positives from these tests must be significantly reduced. The scientists have said the reduction in false positives in cattle is feasible, but that a vaccination programme would be challenging. Despite an intensive, and costly, control program in the United Kingdom, bovine TB persists. Although vaccinating cattle with the human BCG vaccine offers some protection in cattle, doing so is currently illegal within the EU, due to the vaccine’s interference with the skin test used for surveillance.

The Cambridge team worked alongside researchers at the government’s Animal & Plant Health Agency (APHA), to show the importance of specificity – the proportion of uninfected animals that test negative – to making disease control strategies work. The skin test currently in use has a very high estimated specificity of over 99.97%, which means that less than three animals in 10,000 will test falsely positive. However, the test as carried out in Great Britain is thought to have at best an 80% sensitivity – a measure of how many infected animals will correctly test positive – missing around 1 in 5 bovine TB-infected cattle. It is used to determine if animals, herds and countries are officially free of bovine TB.

Vaccinated animals that test positive have to be treated as infected animals. Under European law, if an animal tests positive, it must be slaughtered. The remaining herd is put under movement restrictions and tested repeatedly using both the skin test and post-mortem examinations until it can be shown to be officially clear of infection. Researchers said the duration of movement restrictions is important due to the considerable economic burden they place on farms. Also, the cost to the UK government alone is estimated to amount to half a billion pounds over the last decade; this cost includes visits to farms by veterinarians, tests carried out and compensation for the slaughter of infected animals.

For vaccination to be economically viable and acceptable within the EU, the benefits of vaccination must be great enough to outweigh any increase in testing. A new generation of diagnostic tests, known as ‘Differentiate Vaccinated from Infected Animals’ (DIVA) tests, has opened up the opportunity for the use of BCG within current control programmes. The EU has recently outlined the requirements for changes in legislation to allow cattle vaccination and a recent report from its European Food Safety Authority (EFSA) emphasized the importance of demonstrating that BCG vaccine works, and that DIVA tests can be shown to perform in large-scale field trials.

However, a key factor overlooked in the EU report was that the currently viable DIVA tests have a lower specificity than tuberculin testing; this could lead to vaccinated herds being unable to escape restrictions once a single test-positive animal has been detected, as the more times the herd is tested, the more likely the test is to record a false positive. In their study, the researchers from Cambridge and APHA used herd level models to show that the level of infection can be reduced in vaccinated herds even when DIVA sensitivity is lower than tuberculin skin testing.

However, in order to see this benefit of vaccination over 99.85% of uninfected animals will need to test negative in the DIVA test. This improved accuracy will be necessary to avoid increasing the duration of breakdowns and the number of animals condemned. Using data from previous tests on cattle, the researchers said this level of ‘specificity’ is achievable, though they said there will be challenges associated with improving accuracy. The researchers said, “Currently, there is no gold standard test to diagnose TB in cattle. Cattle that test positive are slaughtered immediately and therefore have rarely developed any physical signs – in fact, only around a half of animals examined post-mortem show physical signs of infection even if they are, indeed, infected.”

Dr Andrew Conlan from the Department of Veterinary Medicine at the University of Cambridge explained “In order for vaccination to be viable, we will need a DIVA test that has extremely high specificity. If the specificity is not good enough, the test will find false positives, leading to restrictions being put in place and a significant financial burden for the farmer. “But validating a test that has a very high specificity will in itself be an enormous challenge. We would potentially need to vaccinate, test and kill a large number of animals in order to be confident the test is accurate. This would be very expensive.”

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Business

West Wales firm fined £75,000 after man killed by escaped cow

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A WEST WALES company has been fined £75,000 following the death of a 75-year-old man, Huw Evans, who was killed by a cow that had escaped from a livestock market. The incident occurred on November 19, 2022, at Whitland Livestock Market in Carmarthenshire, operated by J.J. Morris Limited.

Father-of-two Mr Evans was crossing the junction at North Road and West Street in Whitland when the cow, which was being auctioned, escaped from the market pen. The animal attacked Mr Evans, knocking him down and trampling him. He suffered multiple injuries and was airlifted to the University Hospital of Wales, where he succumbed to his injuries six days later.

A worker from J.J. Morris Limited was also injured during an unsuccessful attempt to recapture the cow. The cow eventually made its way towards Whitland Rugby Club and a railway line before being subdued and put down by Dyfed-Powys Police.

The Health and Safety Executive (HSE) launched an investigation into the incident and found that J.J. Morris Limited had failed to implement essential physical control measures to prevent cattle from escaping. The HSE concluded that the company’s risk assessment was inadequate, referencing control measures that were not in place at the market.

J.J. Morris Limited, based in Haverfordwest, admitted to breaching the Health and Safety at Work Act 1974. The company was fined £75,000 and ordered to pay £5,047.55 in costs by Llanelli Magistrates’ Court on Tuesday, June 20.

In court, Mr Evans’ son, Dafydd, expressed his grief, saying: “Dad was my best friend, and I miss him terribly. He was taken from us too soon. Losing dad has had a tremendous effect on both myself and my brother. Because of this incident, dad’s grandsons will never fully know him personally, and he will not see them grow up.”

Following the hearing, HSE inspector Rhys Hughes remarked, “This tragic incident was foreseeable and preventable. The risk posed by cattle escaping from the livestock mart should have been identified, and effective control measures implemented. The case highlights the importance of following industry guidance, which is readily accessible and outlines the requirements to safely manage cattle.”

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Business

James Evans MS calls for overhaul of ‘toxic’ Meat Promotion Wales

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A CONSERATIVE MS called for Hybu Cig Cymru to be made fully independent amid concerns about a “toxic bullying culture” within the meat promotion organisation.

James Evans, the shadow rural affairs secretary, warned the farming industry is losing faith in Hybu Cig Cymru (HCC), Wales’ meat marketing board.

He said HCC’s chief executive has stood down, two senior executives are leaving and board members are on the verge of resigning.

Mr Evans said: “There have been no board minutes published since 2022, and no up-to-date financial statements or annual reports on their website since 2021.

“This is a very concerning position for HCC to find itself in. The body underpins an industry that’s been valued at more than £1b to Wales.“

The Brecon and Radnorshire MS said a toxic culture of bullying and governance issues within the Welsh Government-owned company are undermining farmers’ confidence.

He said: “A lot of people in the industry, as well, are very concerned about whether the board and the chairman of the board have got the power and the levers that they need to actually turn the organisation around.

“The industry is losing faith.”

During rural affairs questions on June 19, Mr Evans called for a fully independent meat marketing board, run by farmers and processors for farmers and processors.

He told the Senedd: “A lot of farmers I’m speaking to are telling me, ‘Take it away from the Welsh Government, give it back to the industry, give it to the processors, let them directly appoint people onto that board, and, if they don’t perform, they can take them away’.”

Llyr Gruffydd, Plaid Cymru’s shadow rural affairs secretary, warned that the situation is “going from bad to worse”, with two directors resigning this week.

The North Wales representative raised concerns about absence levels and staff turnover as he echoed calls for government intervention.

Pressing Huw Irranca-Davies, the Welsh Government’s rural affairs secretary, he warned of the risk of undermining the faith of HCC levy payers and the reputation of Welsh red meat.

He asked: “For how long will you say that this is someone else’s problem?”

Mr Irranca-Davies replied: “We have to leave it to Hybu Cig Cymru to actually work through these issues and do them properly and assiduously. That is HCCs role…

“It is not for me to step in and, in some ways, tell HCC what to do, or intervene in what are sensitive and delicate discussions with both current and former members.”

Mr Irranca-Davies said he has not heard a universal voice from farmers calling for HCC to be made independent of the Welsh Government.

The rural affairs secretary, who is also responsible for climate change, recognised concerns about governance, saying he has met the chair to seek assurances in the past few weeks.

He told the chamber: “In terms of their day-to-day business and their performance, they’re getting on with it. I’ve had those reassurances that performance is not affected….

“But clearly, I’m aware of the internal governance issues and I’m sure they’re focused on resolving them.”

Mr Irranca-Davies, a former MP and Defra minister under Gordon Brown’s UK Government, pointed out that Heather Anstey-Myers was appointed interim chief executive in January.

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Farming

Strict condition expected to be removed from former farmer’s home in Spittal

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A CALL to remove a strict agricultural condition on a Pembrokeshire property, granted in the 1990s for a vegetable nursery which later suffered with the rise of supermarkets, is expected to get the go-ahead.

In an application recommended for approval at Pembrokeshire County Council’s planning committee meeting of June 25, Mr K Morgan seeks the removal of an agricultural occupancy condition on land at Oakvale, Spittal.

It seeks the removal of a 1993 condition, which reads: “The occupation of the dwelling shall be limited to a person solely or mainly employed, or last employed, in the locality in agriculture (as defined in Section 336(1) of the Town and Country Planning Act 1990), or in forestry or a dependent of such a person residing with him/her, or a widow or widower of such a person”.

Earlier this year, a certificate of Lawfulness was granted at Oakdale; the property having been occupied for over 10 years in breach of the occupancy condition.

An application for a certificate of lawfulness allows an applicant to stay at a development if they can provide proof of occupancy over a prolonged period, normally in excess of four years.

A supporting statement for Mr Morgan’s application says he and his late wife, who had previously run a dairy and arable farm, established a vegetable and plant nursery at Oakvale in 1990, later submitting a successful 1993 application for a dwelling with an agricultural worker condition.

They sold direct from the site and also to local shops, the nursery doing well for a number of years before suffering “with the advent of supermarkets,” ceasing all together in 2010, by which time the property was also serving as a small caravan site, which continues to this day.

Mr Morgan has continued to live at Oakvale whilst managing the caravan site, with his daughter and her family also living on-site to help care for Mr Morgan due to illness.

A report for planners states: “It is possible for the property to be occupied in breach of the condition by any non-qualifying person in perpetuity.  Whilst it is theoretically possible that a future purchaser might comply with the occupancy condition, meaning that the certificate would fall away, the consequences of such an action would result in a loss of upwards of 30 per cent of the value of the property.

“The very low likelihood of this course of action is such that the fall-back position associated with the certificate is a material consideration sufficient to outweigh the conflict with planning policy.”

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