DefinitionDisseminated tuberculosis (TB) is a contagious bacterial infection that has spread from the lungs to other parts of the body through the blood or lymph system.See also: Tuberculosis - pulmonaryAlternative NamesMiliary tuberculosis; Tuberculosis - disseminated; Extrapulmonary tuberculosisCauses, incidence, and risk factorsTuberculosis (TB) infection can develop after inhaling droplets sprayed into the air from a cough or sneeze by someone infected with the Mycobacterium tuberculosis bacteria. Small areas of infection, called granulomas (granular tumors), develop in the lungs.The usual site of tuberculosis is the lungs, but other organs can be involved. In the U.S., most people with primary tuberculous get better and have no further evidence of disease. Disseminated disease develop