Radial testing in the Edge Area

What is a radial test?

This is 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 sections 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 surveillance testing regime in those herds.

All cattle holdings falling within, or straddling, a 3 km radius circle from the new (‘index’) TB breakdown farm will be 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 will also be 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.

Radial TB tests are paid for by the government.

How will I know if my herd is required to undertake radial testing?

Cattle keepers will 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 this test notification letter.

Will my herd be placed under movement restrictions whilst the required radial testing is completed?

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 will be placed under movement restrictions as per normal APHA procedures. Normal overdue procedures also apply for the radial tests and restrictions will be issued if the test results are not received by APHA by the latest due date of the testing window.

What is the testing window for a radial test?

60 days.

What does the radial testing regime involve?

The radial testing regime requires that the eligible herds complete two additional skin tests as outlined below:

  • 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 will revert to their normal frequency of annual routine surveillance testing.

Can a radial test count as a pre-movement test?

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).

In which parts of the Edge Area does the radial testing policy apply?

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

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

For a list of parishes in which herd are subject to six monthly testing in Berkshire, Derbyshire and Hampshire, see the information on the TB Hub.

If a TB breakdown (with lesions and/or culture positive animals) occurs in a section of the Edge area on six monthly testing surveillance, but is within 3km of holdings in an annual testing area, will those holdings be subject to radial testing?

Yes, this breakdown will trigger radial testing of herds located in the annual testing parts of the Edge area.

What is the testing regime of a herd grazing an area subject to annual testing but with a permanent CPH in a six monthly testing area?

The six monthly testing regime will apply, as the default testing regime across a border is for the more rigorous regime to apply.

What is the testing regime of a herd grazing in an area subject to six monthly testing with a permanent CPH in an annual testing area?

Again, the six monthly testing regime would apply, as the default testing regime across a border is for the more rigorous regime to apply.