Final answer:
The disease that is detected through a PPD test is Tuberculosis.
Step-by-step explanation:
The disease that is detected through a PPD test is Tuberculosis. The PPD test, also known as the Mantoux test, involves injecting a small amount of purified protein derivative (PPD) into the skin. If a person is infected with the bacteria that causes tuberculosis, their immune system will react to the PPD and cause a localized swelling at the injection site.