What test is used and how accurate is it?

Information on the tuberculin test which is used to detect Bovine Tuberculosis (TB) in cattle.

The tuberculin skin test is currently used throughout the world to test for tuberculosis. The tuberculin test detects the animal’s defence against disease. It tells if the animal has been in contact with TB. The tuberculin test is not perfect. However, it is the best test currently available. It can be expected to detect approximately 75% of infected cattle at any one test. Herds in which reactors are found are tested a number of times in order to give the best chance of eliminating infection from the herd. It is further known that when the test is used on cattle without disease, it wrongly classifies a non-infected animal as diseased less than once in 1,000 times. Some cows may be less likely to give a positive reaction if they are close to calving.