European regulators have approved a fast blood test for tuberculosis, to replace the slow and painful tuberculin skin test that has been used for more than a century. The new test, called T Spot-TB, will enable doctors to quickly screen people who have been in contact with a TB sufferer and treat those who are infected before they develop the disease and become infectious to others.

The old skin test is crude and unreliable, taking between three and seven days to give a result and sometimes causing painful blistering. The new one - developed by Oxford Immunotec, a UK diagnostics company, in collaboration with Oxford University - gives an accurate reading within a day from a blood sample.