In latent tuberculosis infection, which statement is true?

• A. The bacteria are contained and there are no symptoms.
• B. The bacteria are completely eradicated.
• C. The infection causes immediate severe coughing.
• D. The infection is always contagious.

Answer: (A)

In latent tuberculosis infection, the immune system holds the bacteria in place within granulomas, keeping them alive but dormant. There are no symptoms, and the person is not contagious because the bacteria aren’t actively multiplying or spreading. This state can persist for years, though it can reactivate if the immune system weakens, which is why treatment is often recommended even without symptoms. Detection usually involves a positive TB test or IGRA, with a normal chest X-ray and no signs of active disease.

The other statements aren’t accurate: the bacteria aren’t eradicated—they remain alive but dormant; latent TB does not cause immediate severe coughing; and it is not always contagious.