The Northern Ireland Badger Group has called for a more effective TB test regime to stamp out undetected infection in herds.
Responding to the Northern Ireland Audit Office report, a spokesperson for the group said: “Better testing is key to eradicating TB in cattle. Both the NIAO report and the recent Godfray report on bovine TB have exposed the shortcomings of the current skin test, with recent studies showing that it only detects around 50 per cent of infected cattle.
“The remaining 50 per cent of infected animals are left undetected in herds, which can go on to infect others in the herd or to be traded and infect other herds.”
The group said the standard test leaves a significant amount of residual infection and that it should come as no surprise that herds suffer further breakdowns months or years later. It believes that many of these breakdowns are wrongly attributed to wildlife.
Veterinary scientist Dr Iain McGill, Director of the Prion Interest Group, said: “Continuing to use the SICCT skin test, which has a sensitivity of only 50 per cent, is like trying to catch water with a sieve.
“Telling farmers that their herd is Officially TB-Free based on a test which only works half the time is fraudulent, and vets and farmers need to be explicitly informed of this, otherwise the disease will never be brought under control.”
The badger group has urged DAERA to trial the new Actiphage test in Northern Ireland. Actiphage, which is developed and manufactured by Suffolk firm PBD Biotech, has been licensed by the Animal and Plant Health Agency for exceptional private use in England.
The new test has been used by a Devon vet as part of a private TB eradication strategy which cleared a dairy herd of bovine TB for the first time in six years.
The NIAO report also highlighted the risks posed by cattle movements.
The badger group believes that the distribution of TB strains in cattle and badgers across the Province can only be explained by cattle movement.
“It is evident from the pattern of strain distribution that TB is spread through cattle movement and passed to the local badger population,” the spokesperson said, adding that badgers in Cumbria had been infected by cattle imported from Northern Ireland.
“Culling badgers will do nothing to address the reservoir of infection in cattle herds. Bovine TB is primarily a cattle problem that can only be solved with effective cattle measures, especially better testing”, he added.
“Badgers are a spill-over host infected by cattle and the only proven way to reduce the prevalence of bovine TB in badgers is through vaccination.
“Badger culling has failed to deliver on bovine TB and vaccination offers a wildlife option that will attract broad support from stakeholders and allow the NI bovine TB strategy to move forward.”
A DAERA spokesperson, in response, said the department used all officially approved test instruments as its disposal, and kept new test developments under review to assist in the identification, and subsequent removal of, all infected cattle.
“The single comparative intradermal tuberculin test (SCITT) is the official European Union test for the detection of Bovine Tuberculosis (bTB) in cattle. The sensitivity of the test refers to the ability of the test to correctly identify those cattle with bTB.
“There are a wide range of sensitivities for the SCITT reported in the literature, with sensitivity of over 90 per cent recorded in some reports.
“Sensitivity is improved by using a more severe interpretation of the test and the department expanded its use of more severe interpretation of results earlier this year, with the introduction of a number of additional measures to the programme, in the face of rising bTB incidence.
“Increased frequency of testing in higher risk situations, post mortem inspection in abattoirs and the use of gamma interferon blood testing are amongst other measures that the department uses to identify bTB infected cattle.
“The Gamma Interferon test is permitted for use as a supplementary test, in conjunction with the officially approved TB Skin Test.
“Use of the gamma interferon blood test can assist in identifying infected animals earlier, and removing them from the herd. The department uses this test in high risk breakdown situations.”