Which statement about TB testing is true?

• A. It indicates exposure to TB and infection, but not activity; further testing required
• B. It confirms active TB infection
• C. It indicates immunity due to vaccination
• D. It indicates exposure to TB but infection not present

Answer: (A)

TB tests measure the immune system’s reaction to TB bacteria, showing whether a person has been exposed and infected at some point. A positive result indicates infection, either latent or active, but it does not prove that TB disease is currently active. To determine activity, you need additional evaluation such as symptoms review, chest imaging, and sputum tests to look for active bacteria. Vaccination history can affect results (like BCG causing a false positive on some skin tests), which is why interpretation depends on test type and risk factors. So, the true statement is that TB testing indicates exposure and infection but not activity, and further testing is required to assess for active TB.