Etiology Tuberculosis

∞ generated and posted on 2016.03.03 ∞

Disease affecting especially the lungs that is associated with species of genus Mycobacterium.

Tuberculosis is an infectious disease primarily of the lungs though it has the potential to infect numerous other regions of the body as well and it is caused predominantly by Mycobacterium tuberculosis.

Though the primary cause of is (Mtb), tuberculosis also can be due, though to a much lesser degree, to infection by as well as , and .

Tuberculosis is also known as . Contrast leprosy. See also .

The following is description of the history, ecology, and possible evolutionary tendencies of the etiology of tuberculosis, particularly in terms of :

Current evidence suggests that Mtb was already established as an infection of ancient human populations prior to out of Africa. In these small isolated populations, sustained infection would be favoured by low-virulence pathogens capable of persisting within the human host by chronic or latent infection and transmitting to susceptible new birth cohorts years or decades after initial infection. Higher virulence pathogens with shorter incubation would result in self-terminating epidemics owing to elimination of susceptible hosts . It has been speculated that increases in human population density associated with the Neolithic Revolution in farming and the Industrial Revolution in Europe may have favoured the emergence of Mtb strains with greater virulence and shorter incubation periods . According to this model, as an may have been the predominant mode of Mtb infection in ancient human populations and may have shaped the natural . The current predominant high mortality form of TB would then represent a relatively recent challenge to human . This model is consistent with phylogenetic analysis of global Mtb and with epidemiological differences between the spread of 'modern' and that of 'ancient' Mycobacterium africanum .