A purified protein derivative (PPD) test is used to measure exposure to which disease?

A purified protein derivative (PPD) test is used to measure exposure to which disease?

• A. Tuberculosis
• B. Malaria
• C. Hepatitis B
• D. HIV

Answer: (A)

PPD tests measure exposure to tuberculosis by using tuberculin injected into the skin and checking the skin’s induration response 48–72 hours later. A positive reaction means there has been prior exposure to Mycobacterium tuberculosis, which can reflect latent infection or past disease and prompts further evaluation to determine if active TB is present. It does not test for malaria, hepatitis B, or HIV, which require different diagnostic tests.

PPD tests measure exposure to tuberculosis by using tuberculin injected into the skin and checking the skin’s induration response 48–72 hours later. A positive reaction means there has been prior exposure to Mycobacterium tuberculosis, which can reflect latent infection or past disease and prompts further evaluation to determine if active TB is present. It does not test for malaria, hepatitis B, or HIV, which require different diagnostic tests.