What does a positive Mantoux test suggest?

A positive Mantoux test indicates a possible tuberculosis infection, which is specifically designed to detect exposure to the bacterium Mycobacterium tuberculosis. The test involves the intradermal injection of purified protein derivative (PPD) and is read 48-72 hours later. If the area has a significant induration (swelling), it suggests that the person's immune system has reacted to the tuberculin, indicating a possible past or current infection with tuberculosis.

The test does not diagnose active tuberculosis but indicates an immune response, warranting further evaluation, such as a chest X-ray or sputum test, to assess for active disease. The other options provided do not specifically pertain to the purpose of the Mantoux test and do not reflect the conditions it is intended to evaluate.