Radial and contiguous testing of cattle herds

Radial testing in the Low Risk Area of England

Radial testing diagram - Bovine TB

A targeted TB surveillance skin test carried out on cattle holdings around all new TB breakdowns with lesion and/or culture positive animals identified in the Low Risk Area (LRA).

The purpose of the test is to check for spread of TB to neighbouring cattle herds and to ensure that any undetected source of infection in the locality is identified, thus supplementing the routine TB surveillance testing regime of herds in the LRA. All cattle holdings falling within, or straddling, a 3 km radius circle from the new (‘index’) TB breakdown farm are identified and required to undertake an immediate radial test of all cattle on the holding aged 42 days and older. The radial testing regime is also applied to cattle herds that are outside of the 3 km radius circle that have had regular direct or indirect contact with holdings within the 3 km radial testing area.

Cattle keepers receive a test notification letter from the Animal & Plant Health Agency (APHA) informing them that their herd requires an immediate radial test, specifying the date by which the test is due. The testing window for this immediate radial test usually starts upon receipt of the test notification letter.

All herds fully or partially located within a 3 km radial zone in the LRA are eligible for radial testing, except Licensed Finishing Units (LFUs).

 

As above, all herds fully or partially located within a 3 km radial zone in the LRA are eligible for radial testing, with no exceptions other than for LFUs. However, if you can provide strong evidence that none of the land within a 3 km radial zone is or has been used by your cattle, then, exceptionally, APHA will consider cancelling the radial test and re-instating your herd’s routine surveillance testing regime. If you can provide evidence of non-eligibility you must contact APHA and request a Radial Testing Non-eligibility Declaration Form (TR473), which will need to be countersigned by your private vet. APHA will supply you with a list of field numbers that link your holding to the radial zone and you must supply evidence (detailed in the form) that those fields have not been used by your cattle and will not be used for the foreseeable future (for at least 18 months). APHA will assess any evidence provided and its decision regarding eligibility is final.

Herds are not routinely placed under movement restrictions whilst undergoing radial testing. However, if an inconclusive reactor or reactor is disclosed at a TB test, or lesions suspicious of TB are found in an animal sent to slaughter (known as a slaughterhouse case), then the herd is placed under movement restrictions as per standard procedures. Normal overdue procedures also apply for radial tests, and movement restrictions are placed on the herd if the test results are not received by APHA by the latest due date of the testing window.

Radial TB tests are paid for by the government.

The radial testing regime in the LRA requires that the eligible herds complete a sequence of three additional skin tests:

  • immediate radial test (RAD). This test is carried out after receiving the test notification letter from APHA, unless a whole herd test has been completed with negative results within the 60 days before or after the index case. In such cases, the initial radial test is waived and a RAD6 test is scheduled for six months from the date of the last whole herd test.
  • RAD6 test, carried out six months after completion of the immediate radial test.
  • RAD12 test, carried out twelve months after the RAD6 test.

Thereafter, and provided all the tests are completed with negative results, herds will revert to their normal frequency of routine TB surveillance testing (i.e. every four years for the vast majority of cattle herds in the LRA).

Yes. Herds undergoing radial testing are notified in writing by APHA of the change to their routine herd testing frequency, from four-yearly to annual, for the duration of the radial testing regime. This means that pre-movement testing will be required while the herd is subject to annual testing. Farmers have a period of four weeks from the date of the test notification letter from APHA to make arrangements, if needed, before the pre-movement testing requirement kicks in. Herds in the LRA that are already subject to annual surveillance testing due to their management / type of cattle enterprise (e.g. bull hiring premises or dairy holdings that commercialize raw drinking milk), will continue to require pre-movement testing during the radial testing period.

Yes, provided it has been carried out at the right time (i.e. in the 60 days before the date of the animals’ movement) and no skin test reactors were found.

A 3 km radial zone will be established around this new TB breakdown. If you have fields in the new overlapping radial zone, your herd will be eligible for further radial testing.

In this case, after the RAD12 has been carried out, the herd will resume its normal frequency of routine surveillance testing. The requirement for pre-movement testing in those herds that were not subject to pre-movement testing prior to the radial testing regime will also cease to apply. These changes are notified in writing by APHA following review of the RAD12 test results.

Radial testing in the Edge Area of England 

Radial testing diagram - Bovine TB

A targeted TB surveillance skin test carried out on cattle holdings around all new TB breakdowns with lesion and/or culture positive animals identified in the annual testing parts of the Edge Area.

The purpose of the test is to check for spread of TB to neighbouring cattle herds and to ensure that any undetected source of infection in the locality is identified, thus supplementing the annual routine TB surveillance testing regime of those herds. All cattle holdings falling within, or straddling, a 3 km radius circle from the new (‘index’) TB breakdown farm are identified and required to undertake an immediate radial test of all the cattle on the holding aged 42 days or older. The radial testing regime is also applied to cattle herds that are outside of the 3 km radius circle that have had regular direct or indirect contact with holdings within the 3 km radial testing area.

Cattle keepers receive a test notification letter from APHA informing them that their herd requires an immediate radial test, specifying the date by which the test is due. The testing window for this immediate radial test usually starts upon receipt of the test notification letter.

All herds fully or partially located within a 3 km radial zone in the Edge Area are eligible for radial testing, except Approved Finishing Units (AFUs) without grazing.

 

As above, all herds fully or partially located within a 3 km radial zone in the Edge Area are eligible for radial testing, with no exceptions other than for AFUs without grazing. However if you can provide strong evidence that none of the land within a 3 km radial zone is or has been grazed by your cattle, then, exceptionally, APHA will consider cancelling the radial test and re-instating your herd’s routine surveillance testing regime. If you can provide evidence of non-eligibility you must contact APHA and request a Radial Testing Non-eligibility Declaration Form (TR473), which will need to be countersigned by your private vet. APHA will supply you with a list of field numbers that link your holding to the radial zone and you must supply evidence (detailed in the form) that those fields have not been used by your cattle and will not be used for the foreseeable future (for at least 18 months). APHA will assess any evidence provided and its decision regarding eligibility is final.

Herds are not routinely placed under movement restrictions whilst undergoing radial testing. However, if an inconclusive reactor or reactor is disclosed at a TB test, or lesions suspicious of TB are found in an animal sent to slaughter (known as a slaughterhouse case), then the herd is placed under movement restrictions as per standard procedures. Normal overdue procedures also apply for radial tests, and movement restrictions are placed on the herd if the test results are not received by APHA by the latest due date of the testing window.

Radial TB tests are paid for by the government.

The radial testing regime in the Edge Area requires that eligible herds complete a sequence of two additional skin tests:

  • immediate radial test (RAD). This test is carried out after receiving the test notification letter from APHA, unless a whole herd test has been completed with negative results within the 60 days before or after the index case. In such cases, the initial radial test is waived and a RAD6 test is scheduled for six months from the date of the last whole herd test.
  • RAD6 test, carried out six months after completion of the immediate radial test.

Thereafter, and provided all the tests are completed with negative results, herds revert to their normal frequency of annual routine surveillance testing.

Yes, provided it has been carried out at the right time (i.e. in the 60 days before the date of the animal’s movement) and no skin test reactors were found.

A 3 km radial zone will be established around this new TB breakdown. If you have fields in the new overlapping radial zone, your herd will be eligible for further radial testing.

From 1 January 2018, TB breakdowns with lesion and/or culture positive animals located in the following annual testing counties and part counties trigger radial testing:

 

  • Buckinghamshire
  • East Sussex
  • Leicestershire
  • Northamptonshire
  • Nottinghamshire
  • Berkshire (excluding the area of west Berkshire which is on six-monthly surveillance testing)
  • Derbyshire (excluding the area of west Derbyshire which is on six-monthly surveillance testing)
  • Hampshire (excluding the area of north-west Hampshire which is on six-monthly surveillance testing)

Contiguous testing in England

CON tested farm diagram - Bovine TB

Contiguous testing is carried out to check that infection hasn’t spread from a TB breakdown with lesion and/or culture positive animals (the index herd) to other cattle herds in the locality. All cattle herds, and also goat and camelid herds, which have been grazed or housed in the locality of the index herd are considered by APHA for contiguous testing. Depending on when the index herd was tested before the breakdown started, herds that were in the locality in the previous summer grazing or winter housing period may be eligible for contiguous testing.

Contiguous testing is mainly used in the High Risk Area (HRA) instead of radial testing which is used in the Edge Area and Low Risk Area (LRA). It is also applied to herds that qualify for annual surveillance testing in six-monthly testing parts of the Edge Area.

In the HRA, contiguous testing is applied to all herds in the locality of the index TB breakdown to check that infection hasn’t spread to local cattle herds. As TB is considered to be endemic in wildlife in the HRA, identifying spread to other neighbouring herds isn’t as critical as it is in lower incidence areas, so a smaller 1 km radius from the index farm and associated land boundaries is normally used, compared with 3 km for radial testing.

In six-monthly testing parts of the Edge Area, herds in the locality of the index TB breakdown are assessed and if they are on annual surveillance testing (i.e. they satisfy the criteria for earned recognition), then they are eligible for contiguous testing. Herds on six-monthly surveillance testing are not usually required to undergo contiguous testing due to the high frequency of surveillance testing, however APHA may test in exceptional circumstances.

Cattle keepers receive a test notification letter from APHA informing them that their herd requires an immediate contiguous test, specifying the date by which the test is due. The testing window usually starts upon receipt of the test notification letter.

Herds are not routinely placed under movement restrictions whilst undergoing contiguous testing. However, if an inconclusive reactor or reactor is disclosed at a TB test, or lesions suspicious of TB are found in an animal sent to slaughter (known as a slaughterhouse case), then the herd is placed under movement restrictions as per standard procedures. Normal overdue procedures also apply for contiguous tests, and the herd is placed under movement restrictions if the test results are not received by APHA by the latest due date of the testing window.

Contiguous TB tests are paid for by the government.

Cattle holdings identified by APHA for contiguous testing need to have an immediate TB test of all cattle aged 42 days and older. If the herd has recently completed a whole herd test with negative results, or is due to have a herd test soon, the contiguous test won’t be required.  

Yes, provided it has been carried out at the right time (i.e. in the 60 days before the date of the animal’s movement) and no reactors were found.

After a clear contiguous test, the herd returns to its routine frequency of surveillance testing.