Historical background

Tuberculosis has afflicted man since prehistoric times. Evidence of spinal tuberculosis has been found in neolithic skeletons as well as in early Egyptian remains. The ancient Greeks recognised tuberculosis and called it pthisis to characterise the wasting that occurs in the disease. Tuberculosis was not a major health problem until the Industrial Revolution when crowded urban communities were created thus facilitating the spread of the infection. In Europe, during the seventeenth and eighteenth centuries, as many as a quarter of all deaths could be attributed to tuberculosis. In 1865 Villemin demonstrated the infective nature of the disease when he successfully transmitted the disease to guinea pigs by inoculating them wi.th diseased tissues but it was not until 1882 that Koch discovered the aetiological agent and elucidated the pathogenesis of the disease. With better living conditions and the advent of modem chemotherapy, the incidence of tuberculosis in many developed countries has, since the turn of the century, decreased dramatically. In many low income, developing countries however, there has been no observable decline in incidence. The world situation The current world-wide situation with tuberculosis gives rise to concern. The WorId Health Organisation estimates that 8 million new cases of tuberculosis occurred in 1990. In the same year tuberculosi