Susceptibility to tuberculosis – the importance of the pathogen as well as the host

tuberculosis genetic diversity susceptibility immune responses Tuberculosis remains one of the largest causes of death from an infectious agent, with 8 million new cases and 2 million deaths per annum [1]. It is also estimated that one third of the world's pop-ulation is latently infected with Mycobacterium tuberculosis. The vast majority of these individuals do not develop disease. The improved control of this pathogen will depend on a better under-standing of the many environmental and host genetic factors that determine the progression from latent infection to disease. The most important environmental factor, on a global scale, is HIV infection. Co-infection with HIV increases the risk of developing disease from 10 % in a lifetime to a 10 % annual risk [2]. There is evidence from twin studies of a genetic component to susceptibil-ity to tuberculosis [3] but no single major tuberculosis suscepti