The induration of skin between 6 and 9 mm after a tuberculin test indicates:

Correct option is B

Ans. (b) Doubtful for tuberculosis
Sol. A tuberculin skin test (TST), also known as the Mantoux test, is used to detect latent tuberculosis infection (LTBI). An induration of 6 to 9 mm is considered doubtful, meaning the result is not conclusive and may require further evaluation. Additional tests like chest X-ray or interferon-gamma release assays (IGRAs) are recommended for a clearer diagnosis.
Explanation of each option:
· (a) Tuberculosis positive – Incorrect. A positive test typically requires an induration ≥10 mm in most individuals, or ≥5 mm in high-risk groups.
· (b) Doubtful for tuberculosis – Correct answer. An induration of 6-9 mm is inconclusive and requires further testing.
· (c) Contact with active tuberculosis patients – Incorrect. This is not determined solely by a TST reading.
· (d) No risk for tuberculosis – Incorrect. A 0-5 mm induration is generally considered negative but not necessarily "no risk."