Tuberculosis

Abstract

Tuberculosis (TB) is a communicable, airborne infectious disease caused by the bacterium Mycobacterium tuberculosis (MTB). A quarter of the world's population is infected with TB, affecting all age groups. Infection with MTB results in latent or active disease. Latent infection is associated with a 10% lifetime risk of developing active disease, but this is much higher in those with concurrent immunosuppression. Despite being both preventable and curable, TB remains the leading cause of global death from a single infectious agent. Active disease most commonly affects the lungs but can spread to cause extrapulmonary disease anywhere in the body. Over half of individuals in the UK now present with features of extrapulmonary TB, those with HIV being at particular risk. In all cases, obtaining samples for TB culture is absolutely vital. Standard treatment is with quadruple therapy for 6 months, extended in TB meningitis and often TB bone infection. Adjunctive corticosteroids have proven benefit in TB meningitis and TB pericarditis, and can be considered in other circumstances, such as paradoxical reactions to starting treatment in miliary TB. Despite recent gains in diagnosing and treating TB cases worldwide, the global COVID-19 pandemic is likely to have significantly affected recent progress.