Epidemiology of Tuberculosis
Tuberculosis is still a leading contender for the dubious distinction of being the most important plague of humankind. The World Health Organization (WHO) has estimated that in 1990 7.5 million people had tuberculosis and that there were 2.5 million deaths due to tuberculosis (1). Accentuating the impact of tuberculosis on the world's well-being is its concentration among young adults throughout most of the developing world and its airborne spread from person to person, especially to household members. As noted in Chapter 1, tuberculosis has been exacting a toll for many centuries. Of particular interest from an epidemiological point of view is the reported frequency of skeletal lesions suggestive of tuberculosis among pre-Columbian populations of North America (2). While such lesions were occasionally noted in skeletons of the Late Woodland peoples (800-1050 A.D.), their successors, the Mississippians, had a much higher frequency of tuberculosis-like bony lesions, associated with their coming together in larger and relatively permanent settlements.