What tests are conducted for tuberculosis (TB) screening?

For those who are identified to be at risk of TB infection, the following screening tests will be conducted to detect if an individual has been infected with TB (this could be latent TB or active TB disease).

During TB screening, a blood test is administered, and a Chest X-Ray taken only if necessary as determined by the doctor. In addition, a repeat blood test will be performed 8 weeks after last possible exposure.

This is because if there had been infection with TB, the body may take up to 8 weeks to react and for the test to return positive. This is also known as the test's 'window period'.