A new blood test to detect bTB, has been developed by a team at The University of Nottingham.
Researchers have used this new method to show cattle diagnosed with bovine tuberculosis (bTB) have detectable levels of the bacterium Mycobacterium bovis (M. bovis) in their blood, causing the disease.
This new blood test detects very low levels of mycobacteria in blood using a bacteriophage-based technique developed by The University of Nottingham.
Dr Cath Rees said: “In our paper we show when blood samples from skin test negative cattle were tested for M. bovis cells, all the samples proved negative. However using a 2ml blood sample, viable Mycobacterium tuberculosis complex bacteria (MTC) were detected in 66 per cent of samples from skin test positive animals.
“When the carcasses were inspected, it was found the highest number of bacteria were detected in the animals with visible TB lesions (VL) and 85 per cent of these VL animals were M. bovis positive.
The test delivers results within 48 hours, and the group has patented an improved version of the method which delivers results in six hours, proved to be even more sensitive.
She said: “Using our new more sensitive six-hour method, this figure is even higher - all animals with visible lesions were MTC positive, and even 26 out of 28 animals where the lesions were not yet visible also were positive suggesting M. bovis is commonly found in the circulating blood of infected animals.”
The current skin test is thought to be only 90 per cent sensitive. Early results indicate M. bovis can be detected before the animal becomes positive to the skin test.
Dr Rees said: “Using our bacteriophage-based test the hope is we can help improve herd control by finding animals at the early stages of infection and helping farmers control outbreaks of bTB more rapidly.”