Transmission of Tuberculosis
From the perspective of the organism Mycobacterium tuberculosis, both transmission and pathogenesis are essential for survival and propagation. However, this intracellular bacillus has exhibited itself as an entrenched, opportunistic pathogen, against which our best defenses and control strategies have thus far proven inadequate. Figure 1 depicts many of the biomedical factors known to be important in the propagation of tuberculosis (TB). Not shown are the equally important biosocial factors affecting propagation, such as crowded living conditions, malnutrition, and limited access to health care and effective treatment. This scheme will serve as an overview for this discussion of transmission and pathogenesis.