Inherited predisposition to mycobacterial infection: historical considerations.

Although one third of the world's population is estimated to be infected with Mycobacterium tuberculosis, only one tenth of infected individuals develop clinical disease. There is substantial epidemiological evidence that host genetic factors are important determinants of susceptibility to mycobacterial disease. This paper gives a historical context to the recent exciting advances in the field which have led to the identification of a number of human mycobacterial susceptibility genes.