What is tuberculosis?
What is Tuberculosis (TB)? Tuberculosis (TB) is a chronic infectious disease caused by the bacterium Mycobacterium tuberculosis . It primarily affects the lungs (pulmonary TB), but can also involve other organs (extrapulmonary TB). Causative Agent Mycobacterium tuberculosis Acid-fast, rod-shaped bacillus Aerobic and slow-growing High lipid content in cell wall → resists desiccation and immune killing Mode of Transmission Airborne transmission : Spread by inhalation of droplets (from cough, sneeze, or talk of infected person) Not spread via touching or sharing food Pathogenesis (Basic Overview) Inhalation of bacilli into lungs Bacilli are phagocytosed by alveolar macrophages Granuloma formation : body walls off infection Can lead to: Latent TB (asymptomatic, not contagious) Active TB (symptomatic, contagious) In immunocompromised individuals: risk of reactivation or dissemination (miliary TB) Clinical Features (Pulmonary TB) S...