Which disease is an infectious disease that may affect almost all tissues of the body, especially the lungs?

• A. Gastric ulcer
• B. Hepatitis
• C. Urinary tract infection (UTI)
• D. Tuberculosis

Answer: (D)

Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis that primarily attacks the lungs but can spread to almost every tissue in the body. When inhaled, the bacteria reach the lungs and trigger a immune response that forms granulomas, or tubercles, in the lung tissue. If the bacteria escape containment, they can travel through the bloodstream or lymphatic system and establish infection in other organs, leading to extrapulmonary tuberculosis. This capacity to affect multiple tissues, with the lungs being the most common site, is what makes TB the best match for the description. In contrast, gastric ulcers, hepatitis, and urinary tract infections are typically confined to specific organs and do not inherently spread through the body in the same widespread way.