Which of the following is a method used to help "refresh" the body's memory of TB infection in testing?

Two-step testing is a method used primarily for tuberculosis (TB) screening that helps to identify individuals who may have a latent TB infection. This approach involves administering two separate tuberculin skin tests over a period of time. The first test serves as a baseline, while the second test, given after a set interval (usually 1-3 weeks), helps "refresh" the body's immune response to the TB antigens.

The rationale behind two-step testing is particularly important in situations where individuals may have been previously exposed to TB or have a diminished immune response, making the results of a single test less reliable. By conducting two tests, healthcare providers can more accurately interpret the results, especially in those who may not react to the first test. This method increases the likelihood of detecting a latent infection that might be missed if only a single test were used.

In contrast, the other options do not serve the same purpose as two-step testing. Single-step testing would involve only one tuberculin skin test, which may not adequately identify some cases of latent TB. Yearly skin checks can be part of a routine monitoring schedule but do not specifically focus on refreshing the body's memory of past infections. Blood transfusions are unrelated to TB testing and have no impact on