Which statements confirm active TB infection?

Which statements confirm active TB infection?

• A. The presence of symptoms, positive sputum culture, and chest X-ray
• B. A normal chest X-ray with no symptoms
• C. A negative sputum culture but positive TST
• D. A positive Mantoux test alone

Answer: (D)

Active TB diagnosis relies on microbiologic confirmation along with clinical and radiographic evidence. A positive Mantoux test indicates TB exposure but does not prove the disease is active; many people with a positive TST have latent TB or past exposure rather than active infection. A normal chest X-ray with no symptoms cannot indicate active TB, and a negative sputum culture with a positive TST suggests latent infection rather than active disease. The scenario that includes symptoms, a positive sputum culture, and chest X-ray findings characteristic of TB provides the necessary evidence that TB is active, because it combines clinical illness with microbiologic confirmation and imaging consistent with disease.

Active TB diagnosis relies on microbiologic confirmation along with clinical and radiographic evidence. A positive Mantoux test indicates TB exposure but does not prove the disease is active; many people with a positive TST have latent TB or past exposure rather than active infection. A normal chest X-ray with no symptoms cannot indicate active TB, and a negative sputum culture with a positive TST suggests latent infection rather than active disease. The scenario that includes symptoms, a positive sputum culture, and chest X-ray findings characteristic of TB provides the necessary evidence that TB is active, because it combines clinical illness with microbiologic confirmation and imaging consistent with disease.