Which statement best describes latent TB infection?

Which statement best describes latent TB infection?

• A. Positive TST with a normal chest X-ray and no symptoms; cannot transmit
• B. Negative TST with symptoms; not contagious
• C. Positive TST and abnormal chest X-ray; highly contagious
• D. Positive TST with symptoms; highly contagious

Answer: (A)

Latent TB infection occurs when the tuberculosis bacteria are present but dormant in the body. The person has no symptoms and is not contagious. A positive tuberculin skin test shows TB infection, but it doesn’t distinguish active from latent disease. If the chest X-ray is normal and there are no TB-related symptoms (such as a persistent cough, fever, night sweats, or weight loss), this pattern fits latent TB. In contrast, active TB would typically present with symptoms and an abnormal chest X-ray and could spread the infection to others. Even though it’s not contagious now, treatment is important to prevent progression to active TB, especially in individuals at higher risk.

Latent TB infection occurs when the tuberculosis bacteria are present but dormant in the body. The person has no symptoms and is not contagious. A positive tuberculin skin test shows TB infection, but it doesn’t distinguish active from latent disease. If the chest X-ray is normal and there are no TB-related symptoms (such as a persistent cough, fever, night sweats, or weight loss), this pattern fits latent TB. In contrast, active TB would typically present with symptoms and an abnormal chest X-ray and could spread the infection to others. Even though it’s not contagious now, treatment is important to prevent progression to active TB, especially in individuals at higher risk.