Yes, I had the TB test as a child which came back negative but my younger brother's test was positive which was investigated and it was ascertained that one of the boys he'd been playing with for some time had also been in contact with someone who had been diagnosed/treated for TB. Just goes to show that these tests are pretty good!

Having a tuberculosis (TB) vaccination or TB shot as a child does not necessarily mean that everyone will test positive for TB later in life. The TB vaccine, known as Bacillus Calmette-Guérin (BCG), is often administered in various countries, but its effectiveness can vary, and it is not routinely used in the United States.

The TB skin test (TST) or the TB blood test (interferon-gamma release assays, such as the QuantiFERON-TB Gold test) are commonly used to detect TB infection. These tests measure the body's immune response to the bacteria that cause TB.

If someone received the BCG vaccine, it can cause a positive reaction on the TB skin test. However, a positive TB test doesn't necessarily mean active TB disease. It indicates exposure to the TB bacteria, and additional tests, such as chest X-rays or sputum cultures, may be needed to determine whether TB infection is present.