Which statement best differentiates latent TB infection from TB disease?

Which statement best differentiates latent TB infection from TB disease?

• A. Latent TB is more contagious than TB disease
• B. Latent TB is not active, has no symptoms, cannot be spread
• C. Latent TB always causes fever
• D. Latent TB presents with a productive cough

Answer: (B)

The key point is whether the tuberculosis infection is active and causing illness. In latent TB infection, the bacteria are present but not actively replicating, so there are no symptoms and the person is not contagious. They may have a positive TB test or IGRA, but chest imaging is typically normal and they feel well. In TB disease, the bacteria are active, causing symptoms such as a persistent cough, fever, night sweats, and weight loss, and the person can spread the infection, especially if the lungs are involved. So the statement that latent TB is not active, has no symptoms, and cannot be spread captures the fundamental difference between latent infection and TB disease.

The key point is whether the tuberculosis infection is active and causing illness. In latent TB infection, the bacteria are present but not actively replicating, so there are no symptoms and the person is not contagious. They may have a positive TB test or IGRA, but chest imaging is typically normal and they feel well. In TB disease, the bacteria are active, causing symptoms such as a persistent cough, fever, night sweats, and weight loss, and the person can spread the infection, especially if the lungs are involved. So the statement that latent TB is not active, has no symptoms, and cannot be spread captures the fundamental difference between latent infection and TB disease.