Which of the following is a key consideration when interpreting a TB skin test result in a patient at risk for infection?

• A. Infection with the TB organism is indicated
• B. Active TB disease is definitely diagnosed
• C. Vaccination against TB is confirmed
• D. There is no TB infection present

Answer: (A)

A positive TB skin test indicates that the person has been infected with Mycobacterium tuberculosis at some point. In someone at risk for infection, that finding signals sensitization to TB bacteria and prompts further evaluation to distinguish latent infection from potential progression to active disease. It does not prove active TB, and it does not confirm vaccination status. A negative result can occur in early infection or in people with weakened immune systems, so interpretation should consider timing and immune status. The next steps typically involve checking for TB-related symptoms, obtaining a chest X-ray, and performing microbiologic testing if indicated to determine disease status and appropriate management.