South East of England (low risk area) year end report 2022
Updated 20 November 2023
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Introduction
The Low Risk Area (LRA) of England was established in 2013. In 2014 this area was incorporated into the UK government’s strategy to achieve Officially Tuberculosis-Free (OTF) status for England by 2038. A key action was to recognise the different levels of bovine tuberculosis (TB) in different parts of the country and to vary the approach to control accordingly. Overall, the LRA has a very low and stable incidence of infected herds. The current strategy seeks to rapidly control infection when it arises through:
- high sensitivity testing of affected herds
- temporarily enhanced local surveillance (radial and hotspot testing)
- mandatory pre- and post- movement testing of cattle entering the LRA from higher risk areas of the UK
The aim is to preserve the favourable disease status of this area so that its counties can be declared OTF as soon as possible.
This report describes the frequency and geographical distribution of TB in 2022 in cattle herds in the South East of England. This includes Norfolk, Suffolk, Essex, Kent, West Sussex, Isle of Wight, Surrey, Greater London, Hertfordshire, Bedfordshire, and Cambridgeshire, which are all part of the LRA. In 2022, 32% of all new TB incidents in the LRA were detected in the South East of England.
TB in cattle and other mammals is primarily caused by the bacterium Mycobacterium bovis (M. bovis) and the disease is subsequently referred to as TB in this report. Although other sources may refer to TB ‘breakdowns’, this report will use the term ‘incidents’ throughout.
This report is intended for individuals involved in the control of TB, both locally and nationally. This includes, but is not limited to farmers, veterinarians, policy makers and the scientific community.
Details of the data handling methodology used in this report, a glossary of terms, and the TB control measures adopted in the LRA, can be found in the explanatory supplement for the annual reports 2022.
Types of TB incident
Unless otherwise specified, this report includes all new TB incidents detected during the reporting period, 1 January to 31 December 2022. This includes both ‘Officially Tuberculosis-Free Status Withdrawn’ (OTF-W) and ‘Officially Tuberculosis-Free Status Suspended’ (OTF-S) incidents.
OTF-W incidents are those involving at least one skin test reactor (an animal positive to the Single Intradermal Comparative Cervical Tuberculin, or SICCT test) with either typical lesions of TB identified at post-mortem (PM) meat inspection, or at least one animal with M. bovis-positive culture results from tissue samples collected from carcases during the PM inspection, or both.
OTF-S incidents are triggered by reactors to the skin test, but without subsequent detection of TB lesions or positive culture results in any of those animals.
Cattle industry
The cattle industry in the South East of England is predominantly beef based, as shown in Appendix 1. Over 60% of the cattle in this region are in Norfolk, Kent, Suffolk, and West Sussex. There is a large proportion of small cattle herds (up to 50 animals per herd) in all counties within the region.
There are 3 livestock markets located in Norfolk, Essex and Kent. A collection centre operates in Essex. There are no dedicated sales or collections approved by the Animal and Plant Health Agency (APHA) for onward consignment of TB-restricted cattle direct to a slaughterhouse (SLH). Orange markets (TB-restricted cattle sales) for the sale of negative testing cattle from TB-restricted herds are not permitted in the LRA.
There are 5 active Licensed Finishing Units (LFUs) in this region, and all are subject to annual re-approval visits by APHA.
New TB incidents
There were 46 new TB incidents in the region during 2022, a 77% increase from the 26 incidents reported in 2021 (Figures 1a to d). Nine of those were OTF-W incidents (one less than in 2021), and 37 OTF-S (21 more than in 2021) (Figures 1a to d).
The 9 OTF-W incidents were disclosed in Essex (2) and Surrey (2), and 1 each in Cambridgeshire, Hertfordshire, Isle of Wight, Kent and West Sussex.
Of the 37 OTF-S incidents, 8 were disclosed in West Sussex, 7 in both Essex and Kent, and 5 in Cambridgeshire. There were 3 incidents in both Suffolk and Surrey, 2 in Norfolk, and 1 each in Greater London and Hertfordshire.
No new incidents (OTF-W or OTF-S) were disclosed in Bedfordshire in 2022, which was a decrease from 3 OTF-W and 1 OTF-S incidents in 2021.
Of the 9 OTF-W incidents that started in 2022 in Essex, 6 were closed during 2022 and 2 closed in 2023. One incident was still open at the time of writing.
Figure 1a: Annual number of new TB incidents (OTF-W and OTF-S) in Bedfordshire, Cambridgeshire and Essex, from 2013 to 2022
Figure 1b: Annual number of new TB incidents (OTF-W and OTF-S) in Greater London, Hertfordshire and the Isle of Wight, from 2013 to 2022
Figure 1c: Annual number of new TB incidents (OTF-W and OTF-S) in Kent, Norfolk and Suffolk, from 2013 to 2022
View the data about the number of new TB incidents (OTF-W and OTF-S) in Kent, Norfolk and Suffolk.
Figure 1d: Annual number of new TB incidents (OTF-W and OTF-S) in Surrey and West Sussex, from 2013 to 2022
View the data about the number of new TB incidents (OTF-W and OTF-S) in Surrey and West Sussex.
The headline cattle TB statistics for the South East of England are summarised in Appendix 2.
Unusual TB incidents
An incident that started in August 2022 in Surrey involved what was probably a clinical case in a bull. This animal was born on the holding, but then spent a year and a half at a farm in Gloucestershire before returning to the birth holding in Surrey in the middle of 2020. It was culled after losing body condition and weight in the middle of 2022, and had visible lesions of TB at routine post-mortem meat inspection, from which M. bovis was isolated. Several in-contact animals in the herd were disclosed as reactors during subsequent TB incident testing: 15 skin reactors (7 with visible lesions) and 22 interferon gamma (IFN-γ) blood test reactors (one with visible lesions). M. bovis clade B6-11 was isolated from three of these reactors. This matched the clade isolated from a TB incident on the Gloucestershire farm in 2020, which was phylogenetically ancestral and had 5 Single Nucleotide Polymorphism differences to the Surrey isolates. This genomic information provides strong evidence that the bull was infected in Gloucestershire and then infected many animals in the Surrey holding when it returned.
M. caprae (a member of the Mycobacterium tuberculosis complex, to which M. bovis also belongs) was identified in a beef suckler herd in Essex in November. Six reactors were identified at each of the disclosing routine test and first short interval skin test. Only one of these detected at the short interval test presented with visible lesions of TB at slaughter and M. caprae was isolated. Movement of infected cattle onto the farm cannot be ruled out as a source of this incident because during the last 5 years some cattle movements were recorded mostly to and from shows, but also from holdings in Devon and Staffordshire. The culture-positive reactor was home-bred, suggesting local infection either from other cattle in the herd or from direct or indirect contact with other animals locally. Wild muntjac and fallow deer were observed near the cattle grazing, and there was badger activity in the grazing fields. Cattle had been fed on the ground at grazing and this could have increased the degree of contact with wildlife. This incident continued into 2023.
TB in other species
There were 2 culture-confirmed incidents of M. bovis infection in domestic pigs in the South East region of the LRA in 2022. One incident was reported in Norfolk and one incident in Suffolk, both through post-mortem meat inspection in the slaughterhouse. M. bovis infection was confirmed in both incidents in February 2022 and the incidents were closed before the mid-year point.
The lack of whole genome sequencing (WGS) information for the pig TB incident in Norfolk made it exceedingly difficult to ascertain a potential movement source. However, there has been a history of several culture negative slaughterhouse incidents in supplying linked holdings located in Norfolk, and movements onto these holdings from farms in the Edge Area and High Risk Area. This points towards inward movements of infected pigs as the most likely source of infection.
The pig holding in Suffolk had no previous history of TB. Clade B6-52 (homerange Cornwall) was confirmed in early 2022. A supplying farm had itself received pigs from a Norfolk farm with a history of several slaughterhouse suspect incidents, but were all culture negative. Further investigations to assess movements onto these supplying farms have not revealed conclusive information. The origin of infection is still under investigation.
Disclosing test type
Figure 2 shows the surveillance methods that detected new TB incidents in 2022 for each county separately. As in 2021, routine herd testing (RHT) disclosed the most incidents in the South East (17). This was followed by post-movement tests (9) and radial tests (5).
In 2022, 6-month and 12-month check testing disclosed 2 and 3 incidents, respectively, compared to only one incident by each test the previous year.
Check tests, new herd check tests (NHT), and tracing tests each disclosed one incident in 2022.
There were 3 M. bovis positive slaughterhouse surveillance incidents in Surrey (2) and West Sussex (1) in 2022.
Figure 2: Number of new TB incidents (OTF-W and OTF-S) in the South East in 2022 according to the surveillance method that detected them
Duration of TB incidents
A total of 29 TB incidents were resolved during 2022. Of these, 20 were new TB incidents that started in 2022, while 9 had started in 2021.
In most counties, all OTF-S incidents that were closed in 2022 were resolved in less than 240 days, with the exception of one incident in Kent that was resolved within 550 days. All OTF-W incidents that closed in 2022 were resolved in less than 240 days.
Geographical distribution of TB incidents
As in previous years, new TB incidents in 2022 were spread across the South East of England. Figure 3 shows the location of new TB incidents in 2022, overlaid on a map of cattle density. Incidents were generally disclosed in areas with a higher cattle density.
There were no new incidents (OTF-W or OTF-S) in Bedfordshire, compared to one OTF-S and 3 OTF-W incidents in 2021.
There was a cluster of incidents in the south of Surrey bordering West Sussex, with one OTF-W (labelled 9 in Figure 3) and 2 OTF-S incidents. Whole Genome Sequencing (WGS) replaced genotyping at APHA in 2021. The OTF-W incident was identified as WGS clade B6-85, which has a homerange in the south-west, mainly in Devon and Somerset.
The other OTF-W incident in Surrey, located in the centre of the region, was of an undetermined clade.
In Cambridgeshire, incidents were spread throughout the centre, east and south of the county. The one OTF-W incident (clade B6-14, with a homerange in south-west Wales) was disclosed in the east bordering Suffolk (labelled 3 in Figure 3).
An OTF-W incident occurred in the Isle of Wight (labelled 11 in Figure 3). This was the first OTF-W incident since 2019. Clade B6-11 was detected for this incident, which has a homerange in the west of England, from south Cheshire to Avon and Wiltshire, and in parts of Wales.
OTF-W and OTF-S incidents in Essex were spread throughout the county. The WGS clade of both OTF-W incidents was undetermined. One of the incidents (labelled 6 in Figure 3) occurred in the same area as the 2021 OTF-W incident, which was also caused by an undetermined clade.
In Kent, incidents (OTF-W and OTF-S) mainly occurred in the centre and south of the county, except 2 OTF-S incidents were in the west. The one OTF-W incident was identified as clade B6-85.
There was a cluster of OTF-W and OTF-S incidents around the town of Tring in the west of Hertfordshire (labelled 4 in Figure 3). This is an area where TB incidents have occurred for the last few years. The clade of the one OTF-W incident in 2022 was undetermined. This cluster is the area where a potential hotspot is being set up.
Figure 3: Location of cattle holdings in the South East of England with new TB incidents (OTF-W and OTF-S) in 2022, and cattle holdings with pre-2022 OTF-W incidents still ongoing at the beginning of 2022, overlaid on a cattle density map. Note that ‘OTF-W Introduced 2022’ refers to OTF-W incidents in which cattle movements were the most likely source of infection.
As shown in Figure 4 and Appendix 3 Table 5, OTF-W incidents were attributed to different likely sources of infection. Most incidents were likely caused by introductions of undetected infected cattle, labelled as a ‘purchased’ DRF source.
In 2 incidents (one in Hertfordshire and one in Essex), the infection source was undetermined.
Figure 4: Map of the source of infection pathway recorded with the highest level of certainty, for OTF-W incidents, and the location of OTF-S incidents in the South East of England which started in 2022. Local cattle refer to residual infection and contiguous cattle risk pathways. Purchased refers to cattle movement risk pathways. Wildlife refers to both badger and other wildlife risk pathways.
Radial surveillance zones that were active or completed around OTF-W incidents in the South East of England between 2012 and 2022 are provided in Figure 5. This indicates areas where OTF-W TB incidents have been repeatedly reported over the time period, for example, along the Buckinghamshire border.
Figure 5: Hotspot areas and radial surveillance zones around OTF-W incidents that were active, completed or not instigated in the South East of England during 2022, by year of initiation.
Potential or confirmed TB hotspots
Historical review of WGS phylogeny was carried out to ensure that the ongoing potential TB hotspot area in West Sussex (PHA24) was not closed prematurely, due to a lack of wildlife surveillance data.
A hotspot area was identified in the parish of Tring, Hertfordshire, where 2020 and 2021 OTF-W incidents were detected. There were 3 incidents in this area where genetically identical isolates of M. bovis were disclosed in homebred animals. These isolates belonged to clade B6-62 of the bacterium, which has a homerange in the southern Edge Area, including the neighbouring county of Buckinghamshire. Although these incidents in Hertfordshire were geographically close to the Bedfordshire cluster, there was no epidemiological link because the clade identified there was B6-11, which is very different genetically from B6-62, and the Bedfordshire cluster was attributed to several separate cattle movements from the Edge Area.
The index incident in the Tring area of Hertfordshire could not be attributed to recent or distant introductions of infected cattle to the herd. There was compelling evidence for local infection in this area as supported by the WGS or genotyping results and other epidemiological evidence. A badger carcase collected in February 2022 close to Tring as part of the Southern Edge Area RTA badger survey was eventually confirmed as infected with M. bovis clade B6-62 and identical genomically to the three cattle isolates from the Hertfordshire TB incidents and a cattle isolate from Buckinghamshire just across the county border.
Skin test reactors and interferon gamma test positive animals removed
During 2022, a total of 160 animals were removed as TB test reactors from the South East of England. Of these, 129 were skin test reactors and 31 were positive by the supplementary IFN-γ blood test, as shown in Figure 6a-d.
Compared with 2021, this was an increase in the number of skin test reactors (52) and a decrease in the number of IFN-γ test positive animals (56).
In Bedfordshire and Suffolk there was a large decrease in the number of IFN-γ test positive animals compared to 2021, from 33 to 2, and 13 to 0, respectively.
An increase in the number of positive animals detected by the skin test compared to 2021 occurred in Essex and West Sussex, from 12 to 35, and 7 to 31, respectively.
The IFN-γ test has a higher sensitivity but lower specificity than the comparative skin test and so is likely to disclose more TB positive animals. It can also detect infection at an earlier stage of infection than the skin test.
Figure 6a: Number of cattle that tested positive to the skin test or interferon gamma test and were removed by APHA for TB control reasons in Bedfordshire Cambridgeshire and Essex, from 2017 to 2022
Figure 6b: Number of cattle that tested positive to the skin test or interferon gamma test and were removed by APHA for TB control reasons in Greater london, Hertfordshire and the Isle of Wight, from 2017 to 2022
Figure 6c: Number of cattle that tested positive to the skin test or interferon gamma test and were removed by APHA for TB control reasons in Kent, Norfolk and Suffolk, from 2017 to 2022
Figure 6d: Number of cattle that tested positive to the skin test or interferon gamma test and were removed by APHA for TB control reasons in Surrey and West Sussex, from 2017 to 2022
Main risk pathways and key drivers for TB infection
Evidence collected during APHA veterinary investigations into the source of infection within herds was used to inform this understanding. In 2022, 13 out of 46 (28%) new TB incidents in the South East of England received a preliminary or final APHA veterinary investigation to identify the source of infection.
It can be challenging to retrospectively establish the route of infection for a TB incident herd. Ideally this investigation includes a thorough on-farm investigation and scrutiny of routinely collected data, such as cattle movement records, and the results of WGS where available. Up to 3 hazards and risk pathways were selected for each incident investigated. Each of these potential sources were given a score that reflects the likelihood of that pathway being the true one, based on the available evidence.
Details of the protocol used for these investigations, and the subsequent methodology used to calculate the weighted contribution of the different suspected sources of M. bovis infection can be found in the explanatory supplement to the annual reports 2022.
The key driver of the TB epidemic in the South East of England during 2022 was the purchase of undetected infected cattle.
The movement of cattle with undetected infection continued to be the main pathway of infection for cattle herds in the South East of England in 2022, resulting in a weighted contribution of 82% to the likely sources of infection for herds with new TB incidents (see Appendix 3).
There was some of uncertainty around the source of incidents in 2022, with other or unknown sources having a weighted contribution of 10%. This category is added to those incidents in which there was high uncertainty around the selected pathways (see explanatory supplement to the annual reports 2022 for methodology).
One incident in West Sussex identified exposure to badgers as a likely risk pathway. This resulted in an overall weighted contribution of 5% for wildlife in the South East area.
Exposure to fomites could not be ruled out for one new TB incident in 2022.
Forward look
Current surveillance and incident management measures are keeping the incidence of TB under control. Overall, disease incidence remains low. The recommendation would be continuing to utilise all control measures and to encourage herd biosecurity awareness through communications with farmers’ veterinary providers and farming associations. Based on the current trends, the counties in this region are likely to maintain their target of less than 0.1% of OTF-W incidence by 2025.
The area around Leighton Buzzard in Bedfordshire will need to be closely monitored for further incidents of B6-11, as well as the area around the parish of Tring in the west of Hertfordshire that borders with Buckinghamshire (Edge Area) where a small number of OTF-W incidents associated with clade B6-62 of M. bovis have been detected.
Appendix 1: cattle industry demographics
Table 1a: Number of cattle premises by size band in in Bedfordshire, Cambridgeshire and Essex at 1 December 2022 (RADAR data)
| Size of herds | Number of herds in Bedfordshire | Number of herds in Cambridgeshire | Number of herds in Essex |
|---|---|---|---|
| Undetermined | 3 | 4 | 3 |
| 1 to 50 | 80 | 165 | 206 |
| 51 to 100 | 33 | 33 | 45 |
| 101 to 200 | 12 | 45 | 32 |
| 201 to 350 | 4 | 13 | 17 |
| 351 to 500 | 3 | 3 | 7 |
| Greater than 501 | 2 | 10 | 8 |
| Total number of herds | 137 | 273 | 318 |
| Mean herd size | 72 | 97 | 87 |
| Median herd size | 37 | 31 | 25 |
Table 1b: Number of cattle premises by size band in in Greater London, Hertfordshire and Isle of Wight at 1 December 2022 (RADAR data)
| Size of herds | Number of herds in Greater London | Number of herds in Hertfordshire | Number of herds in Isle of Wight |
|---|---|---|---|
| Undetermined | 1 | 2 | 1 |
| 1 to 50 | 46 | 123 | 55 |
| 51 to 100 | 4 | 31 | 19 |
| 101 to 200 | 3 | 23 | 27 |
| 201 to 350 | 1 | 6 | 8 |
| 351 to 500 | 0 | 1 | 2 |
| Greater than 501 | 0 | 2 | 1 |
| Total number of herds | 55 | 188 | 113 |
| Mean herd size | 28 | 56 | 86 |
| Median herd size | 6 | 24 | 56 |
Table 1c: Number of cattle premises by size band in in Kent, Norfolk and Suffolk at 1 December 2022 (RADAR data)
| Size of herds | Number of herds in Kent | Number of herds in Norfolk | Number of herds in Suffolk |
|---|---|---|---|
| Undetermined | 3 | 4 | 2 |
| 1 to 50 | 333 | 443 | 254 |
| 51 to 100 | 94 | 137 | 69 |
| 101 to 200 | 62 | 86 | 51 |
| 201 to 350 | 29 | 48 | 19 |
| 351 to 500 | 25 | 17 | 9 |
| Greater than 501 | 16 | 25 | 10 |
| Total number of herds | 562 | 760 | 414 |
| Mean herd size | 92 | 93 | 77 |
| Median herd size | 30 | 33 | 30 |
Table 1d: Number of cattle premises by size band in in Surrey and West Sussex at 1 December 2022 (RADAR data)
| Size of herds | Number of herds in Surrey | Number of herds in West Sussex |
|---|---|---|
| Undetermined | 5 | 5 |
| 1 to 50 | 167 | 175 |
| 51 to 100 | 31 | 58 |
| 101 to 200 | 27 | 68 |
| 201 to 350 | 22 | 22 |
| 351 to 500 | 11 | 14 |
| Greater than 501 | 12 | 16 |
| Total number of herds | 275 | 358 |
| Mean herd size | 104 | 112 |
| Median herd size | 25 | 50 |
Table 2a: Number (and percentage of total) of animals by breed purpose in Bedfordshire, Cambridgeshire and Essex at 1 December 2022
| Breed purpose | Number (and percentage of total) cattle in Bedfordshire | Number (and percentage of total) cattle in Cambridgeshire | Number (and percentage of total) cattle in Essex |
|---|---|---|---|
| Beef | 7,481 (75%) | 21,003 (79%) | 22,560 (81%) |
| Dairy | 2,082 (21%) | 4,683 (17%) | 4,000 (14%) |
| Dual purpose | 338 (3%) | 666 (2%) | 1,083 (3%) |
| Unknown | (0%) | 0 (0%) | 1 (0.004%) |
| Total | 9,901 | 26,352 | 27,644 |
Table 2b: Number (and percentage of total) of animals by breed purpose in Greater London, Hertfordshire and Ise of Wight at 1 December 2022
| Breed purpose | Number (and percentage of total) cattle in Greater London | Number (and percentage of total) cattle in Hertfordshire | Number (and percentage of total) cattle in Isle of Wight |
|---|---|---|---|
| Beef | 980 (64%) | 8,337 (79%) | 7,791 (80%) |
| Dairy | 321 (20%) | 1,807 (17%) | 1,813 (18%) |
| Dual purpose | 230 (15%) | 312 (2%) | 125 (1%) |
| Unknown | (0%) | 3 (0.029%) | (0%) |
| Total | 1,531 | 10,459 | 9,729 |
Table 2c: Number (and percentage of total) of animals by breed purpose in Kent, Norfolk and Suffolk at 1 December 2022
| Breed purpose | Number (and percentage of total) cattle in Kent | Number (and percentage of total) cattle in Norfolk | Number (and percentage of total) cattle in Suffolk |
|---|---|---|---|
| Beef | 33,487 (64%) | 56,025 (79%) | 23,038 (72%) |
| Dairy | 17,328 (33%) | 11,637 (16%) | 5,694 (17%) |
| Dual purpose | 1,046 (2%) | 3,088 (4%) | 3,105 (9%) |
| Unknown | 3 (0.006%) | 1 (0.001%) | (0%) |
| Total | 51,864 | 70,751 | 31,837 |
Table 2d: Number (and percentage of total) of animals by breed purpose Surrey and West Sussex at 1 December 2022
| Breed purpose | Number (and percentage of total) cattle in Surrey | Number (and percentage of total) cattle in West Sussex |
|---|---|---|
| Beef | 19,622 (68%) | 23,213 (57%) |
| Dairy | 7,511 (26%) | 15,464 (38%) |
| Dual purpose | 1,507 (5%) | 1,476 (3%) |
| Unknown | (0%) | 6 (0.015%) |
| Total | 28,640 | 40,159 |
Appendix 2: summary of headline cattle TB statistics
Table 3a: Herd-level summary statistics for TB in cattle in Bedfordshire, Cambridgeshire, Essex and Greater London in 2022
| Herd-level statistics | Bedfordshire | Cambridgeshire | Essex | Greater London |
|---|---|---|---|---|
| (a) Total number of cattle herds live on Sam at the end of the reporting period | 168 | 370 | 436 | 75 |
| (b) Total number of cattle herds subject to annual TB testing (or more frequent) at the end of the reporting period (any reason) | 25 | 36 | 22 | 13 |
| (c) Total number of whole herd skin tests carried out at any time in the period | 66 | 95 | 109 | 16 |
| (d) Total number of OTF cattle herds having TB whole herd tests during the period for any reason | 56 | 82 | 102 | 15 |
| (e) Total number of OTF cattle herds at the end of the report period (herds not under any type of Notice Prohibiting the Movement of Bovine Animals (TB02) restrictions) | 164 | 355 | 420 | 73 |
| (f) Total number of cattle herds that were not under restrictions due to an ongoing TB incident at the end of the report period | 166 | 367 | 428 | 75 |
| (g.1) Total number of new OTF-S TB incidents detected in cattle herds during the report period | 0 | 5 | 7 | 1 |
| (g.2) Total number of new OTF-W TB incidents detected in cattle herds during the report period | 0 | 1 | 2 | 0 |
| (h.1) Of the new OTF-W herd incidents, how many occurred in a holding affected by another OTF-W incident in the previous three years? | 0 | 0 | 1 | 0 |
| (h.2) Of the new OTF-W herd incidents, how many could be considered secondary to a primary incident based on current evidence? | 0 | 0 | 0 | 0 |
| (h.3) Of the new OTF-W herd incidents, how many were triggered by skin test reactors or 2 time inconclusive (2xIRs) at routine herd tests? | 0 | 0 | 1 | 0 |
| (h.4) Of the new OTF-W herd incidents, how many were triggered by skin test reactors or 2xIRs at other TB test types (such as forward and back-tracings, contiguous, check tests)? | 0 | 1 | 1 | 0 |
| (h.5) Of the new OTF-W herd incidents, how many were first detected through routine slaughterhouse TB surveillance? | 0 | 0 | 0 | 0 |
| (i.1) Number of new OTF-S incidents revealed by enhanced TB surveillance (radial testing) conducted around those OTF-W herds | 0 | 0 | 0 | 1 |
| (i.2) Number of new OTF-W incidents revealed by enhanced TB surveillance (radial testing) conducted around those OTF-W herds | 0 | 0 | 0 | 0 |
| (j) Number of OTF-W herds still open at the end of the period (including any ongoing OTF-W incidents that began in a previous reporting period) | 2 | 2 | 2 | 0 |
| (k) Number of OTF-W herds still open at the end of the period that are within a finishing unit | 0 | 1 | 0 | 0 |
| (l) New confirmed (positive M. bovis culture) incidents in non-bovine species detected during the report period (indicate host species involved) | 0 | 0 | 0 | 0 |
Table 3b: Herd-level summary statistics for TB in cattle in Hertfordshire, Isle of Wight, Kent and Norfolk in 2022
| Herd-level statistics | Hertfordshire | Isle of Wight | Kent | Norfolk |
|---|---|---|---|---|
| (a) Total number of cattle herds live on Sam at the end of the reporting period | 238 | 137 | 685 | 981 |
| (b) Total number of cattle herds subject to annual TB testing (or more frequent) at the end of the reporting period (any reason) | 32 | 14 | 38 | 19 |
| (c) Total number of whole herd skin tests carried out at any time in the period | 64 | 32 | 172 | 201 |
| (d) Total number of OTF cattle herds having TB whole herd tests during the period for any reason | 46 | 29 | 153 | 198 |
| (e) Total number of OTF cattle herds at the end of the report period (herds not under any type of Notice Prohibiting the Movement of Bovine Animals (TB02) restrictions) | 231 | 137 | 668 | 958 |
| (f) Total number of cattle herds that were not under restrictions due to an ongoing TB incident at the end of the report period | 236 | 137 | 684 | 980 |
| (g.1) Total number of new OTF-S TB incidents detected in cattle herds during the report period | 1 | 0 | 7 | 2 |
| (g.2) Total number of new OTF-W TB incidents detected in cattle herds during the report period | 1 | 1 | 1 | 0 |
| (h.1) Of the new OTF-W herd incidents, how many occurred in a holding affected by another OTF-W incident in the previous three years? | 0 | 0 | 0 | 0 |
| (h.2) Of the new OTF-W herd incidents, how many could be considered secondary to a primary incident based on current evidence? | 0 | 0 | 0 | 0 |
| (h.3) Of the new OTF-W herd incidents, how many were triggered by skin test reactors or 2xIRs at routine herd tests? | 0 | 0 | 0 | 0 |
| (h.4) Of the new OTF-W herd incidents, how many were triggered by skin test reactors or 2xIRs at other TB test types (such as forward and back-tracings, contiguous, check tests)? | 1 | 1 | 1 | 0 |
| (h.5) Of the new OTF-W herd incidents, how many were first detected through routine slaughterhouse TB surveillance? | 0 | 0 | 0 | 0 |
| (i.1) Number of new OTF-S incidents revealed by enhanced TB surveillance (radial testing) conducted around those OTF-W herds | 1 | 0 | 1 | 0 |
| (i.2) Number of new OTF-W incidents revealed by enhanced TB surveillance (radial testing) conducted around those OTF-W herds | 0 | 0 | 0 | 0 |
| (j) Number of OTF-W herds still open at the end of the period (including any ongoing OTF-W incidents that began in a previous reporting period) | 2 | 0 | 0 | 0 |
| (k) Number of OTF-W herds still open at the end of the period that are within a finishing unit | 0 | 0 | 0 | 0 |
| (l) New confirmed (positive M. bovis culture) incidents in non-bovine species detected during the report period (indicate host species involved) | 0 | 0 | 0 | 1 (pig) |
Table 3c: Herd-level summary statistics for TB in cattle in Suffolk, Surrey and West Sussex in 2022
| Herd-level statistics | Suffolk | Surrey | West Sussex |
|---|---|---|---|
| (a) Total number of cattle herds live on Sam at the end of the reporting period | 557 | 358 | 471 |
| (b) Total number of cattle herds subject to annual TB testing (or more frequent) at the end of the reporting period (any reason) | 18 | 32 | 29 |
| (c) Total number of whole herd skin tests carried out at any time in the period | 118 | 87 | 94 |
| (d) Total number of OTF cattle herds having TB whole herd tests during the period for any reason | 117 | 81 | 84 |
| (e) Total number of OTF cattle herds at the end of the report period (herds not under any type of Notice Prohibiting the Movement of Bovine Animals (TB02) restrictions) | 542 | 346 | 448 |
| (f) Total number of cattle herds that were not under restrictions due to an ongoing TB incident at the end of the report period | 555 | 353 | 465 |
| (g.1) Total number of new OTF-S TB incidents detected in cattle herds during the report period | 3 | 3 | 8 |
| (g.2) Total number of new OTF-W TB incidents detected in cattle herds during the report period | 0 | 2 | 1 |
| (h.1) Of the new OTF-W herd incidents, how many occurred in a holding affected by another OTF-W incident in the previous three years? | 0 | 0 | 0 |
| (h.2) Of the new OTF-W herd incidents, how many could be considered secondary to a primary incident based on current evidence? | 0 | 0 | 0 |
| (h.3) Of the new OTF-W herd incidents, how many were triggered by skin test reactors or 2xIRs at routine herd tests? | 0 | 0 | 0 |
| (h.4) Of the new OTF-W herd incidents, how many were triggered by skin test reactors or 2xIRs at other TB test types (such as forward and back-tracings, contiguous, check tests)? | 0 | 0 | 0 |
| (h.5) Of the new OTF-W herd incidents, how many were first detected through routine slaughterhouse TB surveillance? | 0 | 2 | 1 |
| (i.1) Number of new OTF-S incidents revealed by enhanced TB surveillance (radial testing) conducted around those OTF-W herds | 0 | 1 | 1 |
| (i.2) Number of new OTF-W incidents revealed by enhanced TB surveillance (radial testing) conducted around those OTF-W herds | 0 | 0 | 0 |
| (j) Number of OTF-W herds still open at the end of the period (including any ongoing OTF-W incidents that began in a previous reporting period) | 0 | 2 | 1 |
| (k) Number of OTF-W herds still open at the end of the period that are within a finishing unit | 0 | 0 | 1 |
| (l) New confirmed (positive M. bovis culture) incidents in non-bovine species detected during the report period (indicate host species involved) | 1 (pig) | 0 | 0 |
Table 4a: Animal-level summary statistics for TB in cattle in Bedforshire, Cambridgeshire, Essex and Greater London during 2022
Note (c) Reactors detected during year per incidents disclosed during year, reactors may be from incidents disclosed in earlier years, as any found through testing during the report year count here.
Note (g) SLH cases confirmed by culture of M. bovis, not all cases reported are submitted for culture analysis. All cases reported are from any period prior to or during restrictions.
| Animal-level statistics (cattle) | Bedfordshire | Cambridgeshire | Essex | Greater London |
|---|---|---|---|---|
| (a) Total number of cattle tested with tuberculin skin tests or additional IFN-γ blood tests in the period (animal tests) | 8,220 | 11,334 | 7,791 | 801 |
| (b.1) Reactors detected by tuberculin skin tests during the year | 4 | 17 | 35 | 2 |
| (b.2) Reactors detected by additional IFN-γ blood tests (skin-test negative or IR animals) during the year | 2 | 1 | 0 | 0 |
| (c) Reactors detected during year per incidents disclosed during year | 0.00 | 3.00 | 3.89 | 2.00 |
| (d) Reactors per 1,000 animal tests | 0.73 | 1.59 | 4.49 | 2.50 |
| (e.1) Additional animals slaughtered during the year for TB control reasons (dangerous contacts, including any first time IRs) | 1 | 0 | 0 | 0 |
| (e.2) Additional animals slaughtered during the year for TB control reasons (private slaughters) | 0 | 0 | 0 | 0 |
| (f) SLH cases (tuberculous carcases) reported by the Food Standards Agency (FSA) during routine meat inspection | 0 | 1 | 0 | 0 |
| (g) SLH cases confirmed by culture of M. bovis | 0 | 0 | 0 | 0 |
Table 4b: Animal-level summary statistics for TB in cattle in Hertfordshire, Isle of Wight, Kent and Norfolk during 2022
Note (c) Reactors detected during year per incidents disclosed during year, reactors may be from incidents disclosed in earlier years, as any found through testing during the report year count here.
Note (g) SLH cases confirmed by culture of M. bovis, not all cases reported are submitted for culture analysis. All cases reported are from any period prior to or during restrictions.
| Animal-level statistics (cattle) | Hertfordshire | Isle of Wight | Kent | Norfolk |
|---|---|---|---|---|
| (a) Total number of cattle tested with tuberculin skin tests or additional IFN-γ blood tests in the period (animal tests) | 6,889 | 4,225 | 19,285 | 15,786 |
| (b.1) Reactors detected by tuberculin skin tests during the year | 11 | 1 | 13 | 2 |
| (b.2) Reactors detected by additional IFN-γ blood tests (skin-test negative or IR animals) during the year | 11 | 1 | 2 | 0 |
| (c) Reactors detected during year per incidents disclosed during year | 11.00 | 2.00 | 1.88 | 1.00 |
| (d) Reactors per 1,000 animal tests | 3.19 | 0.47 | 0.78 | 0.13 |
| (e.1) Additional animals slaughtered during the year for TB control reasons (dangerous contacts, including any first time IRs) | 0 | 0 | 0 | 0 |
| (e.2) Additional animals slaughtered during the year for TB control reasons (private slaughters) | 0 | 0 | 11 | 0 |
| (f) SLH cases (tuberculous carcases) reported by the Food Standards Agency (FSA) during routine meat inspection | 0 | 1 | 1 | 2 |
| (g) SLH cases confirmed by culture of M. bovis | 0 | 0 | 0 | 0 |
Table 4c: Animal-level summary statistics for TB in cattle in Suffolk, Surrey, and West Sussex during 2022
Note (c) Reactors detected during year per incidents disclosed during year, reactors may be from incidents disclosed in earlier years, as any found through testing during the report year count here.
Note (g) SLH cases confirmed by culture of M. bovis, not all cases reported are submitted for culture analysis. All cases reported are from any period prior to or during restrictions.
| Animal-level statistics (cattle) | Suffolk | Surrey | West Sussex |
|---|---|---|---|
| (a) Total number of cattle tested with tuberculin skin tests or additional IFN-γ blood tests in the period (animal tests) | 12,545 | 11,860 | 16,547 |
| (b.1) Reactors detected by tuberculin skin tests during the year | 6 | 7 | 31 |
| (b.2) Reactors detected by additional IFN-γ blood tests (skin-test negative or IR animals) during the year | 0 | 7 | 7 |
| (c) Reactors detected during year per incidents disclosed during year | 2.00 | 2.80 | 4.22 |
| (d) Reactors per 1,000 animal tests | 0.48 | 1.18 | 2.30 |
| (e.1) Additional animals slaughtered during the year for TB control reasons (dangerous contacts, including any first time IRs) | 0 | 0 | 0 |
| (e.2) Additional animals slaughtered during the year for TB control reasons (private slaughters) | 0 | 0 | 0 |
| (f) SLH cases (tuberculous carcases) reported by the Food Standards Agency (FSA) during routine meat inspection | 2 | 2 | 1 |
| (g) SLH cases confirmed by culture of M. bovis | 0 | 2 | 1 |
Appendix 3: suspected sources of M. bovis infection for all of the new OTF-W and OTF-S incidents identified in the report period
In 2022, 13 out of 46 (28%) new TB incidents in the South East of England received a preliminary or final APHA veterinary investigation to identify the source of infection.
Each TB incident could have up to three potential risk pathways identified. Each risk pathway is given a score that reflects the likelihood of that pathway bringing TB into the herd. The score is recorded as either:
- definite (score 8)
- most likely (score 6)
- likely (score 4)
- possible (score 1)
The sources for each incident are weighted by the certainty ascribed. Any combination of definite, most likely, likely, or possible can contribute towards the overall picture for possible routes of introduction into a herd.
If the overall score for a herd is less than six, then the score is made up to six using the ‘Other or unknown source’ option. Buffering up to six in this way helps to reflect the uncertainty in assessments where only ‘likely’ or ‘possible’ sources are identified.
Table 5 combines the data from multiple herds and provides the proportion of pathways in which each source was identified, weighted by the certainty that each source caused the introduction of TB.
The output does not show the proportion of herds where each pathway was identified (this is skewed by the certainty calculation).
WGS of M. bovis isolates can be a powerful tool in identifying a likely source of infection, however WGS clades have not been determined for OTF-S herds. As a result of varying levels of uncertainty, only broad generalisations should be made from these data. A more detailed description of this methodology is provided in the explanatory supplement for the annual reports 2022.
Table 5: Suspected sources of M. bovis infection for all new OTF-W and OTF-S incidents identified in the South East of England in 2022
Please note each TB incident could have up to 3 potential pathways, so totals may not equate to the number of actual incidents that have occurred.
| Source of infection | Possible (1) | Likely (4) | Most likely (6) | Definite (8) | Weighted contribution |
|---|---|---|---|---|---|
| Badgers | 0 | 0 | 0 | 0 | 0% |
| Cattle movements | 1 | 4 | 8 | 2 | 89% |
| Contiguous | 1 | 0 | 0 | 0 | 1% |
| Residual cattle infection | 1 | 0 | 0 | 0 | 1% |
| Domestic animals | 0 | 0 | 0 | 0 | 0% |
| Non-specific reactor | 0 | 0 | 0 | 0 | 0% |
| Fomites | 1 | 0 | 0 | 0 | 1% |
| Other wildlife | 0 | 0 | 0 | 0 | 0% |
| Other or unknown source | 1 | 0 | 0 | 0 | 8% |