According to CDC guidelines, what induration size is considered positive in HIV-positive individuals or those with HIV risk factors?

According to CDC guidelines, what induration size is considered positive in HIV-positive individuals or those with HIV risk factors?

• A. 5 mm
• B. 10 mm
• C. 15 mm
• D. 20 mm

Answer: (A)

In people with HIV or HIV risk factors, the amount of swelling that counts as a positive reaction to the TB skin test is smaller because their immune response can be blunted. A 5 millimeter or larger induration is considered positive. This lower threshold helps identify TB infection early in those at greatest risk, so they can be evaluated promptly for active disease and consider latent TB treatment if appropriate. For context, the thresholds vary by risk level: a larger induration is required to be positive in lower-risk groups (10 mm for moderate risk, 15 mm for those with minimal or no known risk). Also, some individuals with advanced immunosuppression can have false negatives (anergy), so if suspicion remains high, alternative testing or repeat evaluation may be needed.

In people with HIV or HIV risk factors, the amount of swelling that counts as a positive reaction to the TB skin test is smaller because their immune response can be blunted. A 5 millimeter or larger induration is considered positive. This lower threshold helps identify TB infection early in those at greatest risk, so they can be evaluated promptly for active disease and consider latent TB treatment if appropriate.

For context, the thresholds vary by risk level: a larger induration is required to be positive in lower-risk groups (10 mm for moderate risk, 15 mm for those with minimal or no known risk). Also, some individuals with advanced immunosuppression can have false negatives (anergy), so if suspicion remains high, alternative testing or repeat evaluation may be needed.