Bovine TB failings in Oxfordshire and beyond in 2023
The “Year End Descriptive Epidemiology Reports” for Bovine TB control were published by APHA online on 24th October for the Edge Area counties of: Berkshire, Buckinghamshire, Cheshire, Derbyshire, East Sussex, Hampshire, Leicestershire, Northamptonshire, Nottinghamshire, Oxfordshire and Warwickshire.
The report for Oxfordshire is the most extensive of the county reports (see here). What does it tell us about the progress made on bTB control as measured by cattle herds withdrawn (so-called ‘confirmed’ breakdowns) in Oxfordshire? And what does it tell us about APHA’s approach to epidemiological standards? It looks like they are still blaming wildlife by default………….
Ups and Downs
In Oxfordshire, following a continual decrease in OTF-W (Officially TB Free Withdrawn) breakdown incidents since 2018, the number of incidents rose from 31 in 2022 to 41 in 2023, which is similar to the numbers of incidents in 2020 (47 OTF-W). The number of OTF-S (Officially TB Free Suspended) incidents also rose slightly from 25 in 2022 to 28 in 2023. This is the highest number of OTF-S incidents in the last 10 years.
The APHA say that having originated in West Oxfordshire, East Oxfordshire is now the main driver of bTB spread in the county, especially during the last three years, with an increase of OTF-W incidents in 2023. This suggests that TB is actively spreading in East Oxfordshire, despite the initial decrease in the total number of incidents and following use of interferon gamma (IFN-γ) blood testing and increased SICCT testing in 2018.
Unscientific inference
Despite APHA’s consistent inability to scientifically attribute bTB disease benefit to badger culling, they casually state that persistent incidents have decreased due to “implementing control measures such as badger culling since 2019”.
In 2023, additional Defra approved ancillary tests (IFN-Y & IDEXX) for use in Oxfordshire to “remove infection in incidents where the level of reinfection from purchases and wildlife was believed to be low, but where the effect of residual infection was preventing incidents from becoming clear”. It is not clear what exactly leads APHA to believe infection in wildlife is low in this instance, when they consistently say that it is high elsewhere. Perhaps due to removal by shooting of around 2,500 badgers in Oxfordshire’s Cull Area 49 (West Oxfordshire) in an area overlapping with Gloucestershire?
Deer are next in the blame game
Reports of suspicion of TB in wild deer increased in 2023. This is likely due to the creation in 2022 of the Oxfordshire Cluster Project, which offered training to local deer stalkers to identify typical lesions of TB in game carcasses.
Not surprisingly with greater checks, wild deer carcasses with TB lesions were reported to APHA in 2023: two roe deer, one fallow and one muntjac. All were sampled and sent for TB culture and bTB clade B6-62 was confirmed in all of them which is the common clade in Oxfordshire cattle. Whole Genome Sequencing (WGS) was employed by APHA to link “incidents to specific cattle incidents in the same geographical area”, with a claim of ”further evidence of the relationship between cattle and local wildlife in the transmission of TB”, without evidence of the relationship and direction of infection. Inconclusive epidemiology.
The Bird-flu distraction claim
The APHA also claim that an increase in recorded bTB incidence in cattle in 2023 followed an emergency interim action in December 2021, diverting APHA staff to addressing the 2021-2023 highly pathogenic avian influenza (HPAI) outbreaks. Gamma testing was prioritized to the LRA and Edge Area counties on 12-month testing (not 6-monthly) during that time, further reducing the number of tests in Oxfordshire. APHA view this change in gamma policy as likely to have contributed to slowing the decrease in incidence in 2022 and for the increase in 2023, amongst other factors. However, in addition, the reduction of EU finance after Brexit was a driver to reducing disease eradication effort.
APHA in a muddle?
APHA say that licensed intensive badger culling operations started in the west side of Oxfordshire in 2019, while the first large area in Oxfordshire was Cull Area 49 commencing 2020. In 2021 a Cull Area 61 further north was commenced with an additional Cull Area 69 on the East side of the county starting 2022.
Guess-estimated Cull Area boundaries in Oxfordshire with year of start
APHA claim that badger culling has “probably started to have a positive impact in western areas of the county but not yet in the… east of the county where TB is spreading further east.” This is simply more unevidenced guesswork and is completely unacceptable, probably driven by one or two individuals who have over-invested in badger blame and who stands to lose a lot from being wrong about the whole sad process and because they have mislead hundreds of others.
Clusters
APHA claim that “clusters” of bTB breakdowns provide evidence of local spread, and say that where local cattle purchase has not occurred, cattle herd incidents are most likely caused by wildlife. Once again they are speculating – pointing by default to badgers where there is no obvious purchase of cattle to blame; undetected disease in the herd and very many other possibilities are once again ignored.
Clusters were first identified in Oxfordshire in 2017. WGS investigations and ‘phylogenetic trees’ have increased knowledge of the transmission of M. bovis, but APHA say that they ”cannot always” answer the direction of transmission and/or ancestry due to limited numbers of isolates. But in truth this is not possible in any of their investigations – they need to stop pretending and misleading readers of their reports. And the farmers should not put up with these misdescriptions – it is costing them dearly to be given inaccurate advice.
We know that badgers have been tested for bTB in cluster areas but how this work is being done is hidden in secrecy.
Unevidenced ‘risk pathways’ again
APHA list the following main ‘risk pathway’s and key drivers for TB infection within Oxfordshire in 2023 in the following order:
- exposure to infected local wildlife
- movement of undetected infected cattle
- residual infection from previous incidents.
Astonishingly, the APHA still put infected wildlife at the top of their list of risk factors for TB incidents in cattle in 2023. Could this be because they are still using the discredited Disease Report Form (DRF), which blames badgers by default, when there is no clear infection route from cattle? There was an impression in 2023 that the DRF was being phased out but APHA seem trapped in a neglectful poorly functioning system where blaming badgers fills the gap of attribution being uncertain due to inadequate investigation and testing.
These incidents are far more likely to be from undetected disease in cattle. Once again without evidence, APHA still pedal the same old rhetoric that they have still been telling vets and farmers: “most common source of transmission from wildlife identified during on-farm investigations were potentially infected badgers, but the presence of other wildlife species such as wild deer is increasingly reported in some areas”. Adding as some kind of ‘get out of jail if wrong’ statement that there is “high uncertainty as to their [bagders] role in transmitting TB to cattle”. It’s an utter disaster area. They also admit that distinguishing source attribution between badgers and residual cattle infection in recurrent incidents is difficult, but claim it is likely “a combination” of both factors. Muddling cattle movements with unevidenced badger infection somehow suits their old arguments but muddles vet and farmer understanding. Basically, the APHA are still pointing to badgers as an important source of infection, misleading the industry without any evidence. .
Tricking the vets and farmers – residual infection is the key
As now appreciated by the BBC 2 documentary on the work of the Save Me Trust and Dick Sibley in Devon and elsewhere – looking at the APHA reporting of 3 yearly recurrence data and recurrence in the lifetime herd history, you can see that 82% of incidents reported across Oxfordshire were in herds with a history of TB during the herd’s lifetime, including more than 3 years previously. Recurrence of bTB is due to undetected residual infection coupled with cattle movements. It is the result of insensitive tests. This is where the problem lies and with current approaches APHA have no chance of disease control – it is one huge failure.
Whilst APHA do accept residual cattle infection as an important problem and note the tendency of incidents in Oxfordshire to be more chronic and recurrent, they still cling on to badger blame. Why they do so is extraordinary, but relates to a shrinking group of individuals so wedded to it being the case; as a group they dare not change position. The only thing that will make that happen is if farmers and vets stand up to how they are being grossly mislead by those who effectively control them.
Introduction of systematic supplementary Gamma testing since 2018 has increased the overall sensitivity of testing in herds and reduced the likelihood of infection being left in the herd at the end of a TB incident. Good progress was being made but (as above) this supplementary testing has been reduced in the last two years and targeted to a limited number of herds with recurrent and persistent incidents. Absolute madness – why are the livestock farmers not jumping up and down about this slackening off?
Sadly, the picture is the same across other counties. In Cheshire, for example, 86% of incidents reported across the region were in herds with a history of TB in the herds lifetime, including in the three previous years. It’s really not rocket science.
A messy complicated picture
The number of herd incidents of TB per year in Oxfordshire remained high over the last 5 years, with a decreasing trend in 2021 and 2022, before reverting in 2023 to the same levels as seen in 2020. The epidemiological picture has become more complex in recent years with multiple clusters, some of which have only recently become apparent. APHA say that this “does not favour the long-term objective of reducing OTF-W incidence to less than 1% in Oxfordshire by 2038.”
The future look bleak
British farming is staring down the barrel of an even greater bTB disaster. APHA and their badger blame game story are in danger of making a new High Risk Area out of the Edge Area and risk infecting the entire country.
APHA are at least emphasizing the importance of the early detection of infection through more frequent surveillance testing of cattle herds, alongside the use of mandatory gamma testing on all OTF-W incidents. And now alongside other Defra approved ancillary testing by informed case management, recognising lack of sensitivity of current tests (SICCT) as a potential issue. But not with sufficient emphasis and determination to mend the current broken system. Disciplined pre and post movement testing are still approached in an ineffective way, despite their pivotal role in stopping transmission. This has been clearly known and ignored since 2018 when the issue was pointed out to the Godfray Review..
APHA’s continued blaming of badgers for a significant proportion of cattle bTB infections is now a real barrier to disease control that risks pulling the beef and dairy industries further into disaster. The scientific evidence APHA skews to blame badgers is ridiculous and as the 2038 ambition dissolves, the stakes are being raised higher and higher. Who will be the first to realise and take urgent action to prevent the worsening of this national disaster? Those in charge might answer.