Defra to monitor cow-side TB blood test progress

The further development and evaluation of the first blood-based, cow-side test for rapid and early bovine tuberculosis (bTb) diagnosis will be monitored by Defra.

A team of US researchers at Los Alamos National Laboratory applied an “ultra-sensitive” strategy called lipoprotein capture to successfully detect TB in a small experimental sample.

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The method directly detected TB in infected cattle “very early” after infection, the study said.

Reacting to the study, published in Analytical Sciences, a Defra spokesperson said: “This is a very early experimental result using blood samples from a small number of animals.

“We will continue to monitor any further results from this test as we do with all emerging bTB tests.”

‘TB education needed’

Den Leonard, director at Lambert Leonard and May Farm Animal Veterinary Surgeons, told Farmers Weekly he believes the current testing is sufficient and capable. He said: “There is simply no need for any new tests.”

His stance is that while the single intradermal comparative cervical test (SICCT) or “skin test” has low sensitivity, it soon discovers infected areas because “so many tests are done on a farm or area basis”.

He said: “The existing tests perform more than well everywhere in the developed world that doesn’t contain an infected wildlife burden, and this includes the low-risk area and Scotland, as well as the Isle of Man.

“Also, new tests that are not specific enough will cause absolute chaos if they are adopted wholesale.”

He said better education of stakeholders by the government and practicing vets is needed.

Questions raised

Gloucestershire-based veterinarian Roger Blowey stressed that the test was at the experimental stage, with many questions that need to be answered.

He said: “There are no results to show its potential field application – for example, does it identify early infection, like the skin test and gamma test, or later infection, like DPP and Enferplex?

“We need to know what the test’s specificity and sensitivity are and whether taking the blood samples is easy or whether special conditions are needed like with the gamma test.

“We already have the DPP and Enferplex antibody tests and PCR + phage antigen tests that so far are not licensed for field use in the UK.”