Global epidemiology of tuberculosis. Morbidity and mortality of a worldwide epidemic.

This article describes the global epidemiology of tuberculosis and reviews recent estimates of tuberculosis incidence and mortality in the world. The highest prevalence of tuberculosis infection and estimated annual risk of tuberculosis infection are in sub-Saharan Africa and Southeast Asia. Overall, almost 3.8 million cases of tuberculosis were reported in the world in 1990, of which 49% were in Southeast Asia. From the period 1984 through 1986 to the period 1989 through 1991, notification rates increased in all World Health Organization regions, except the American and the European regions. In 1990, there were an estimated 7.5 million cases of tuberculosis and 2.5 million deaths worldwide. The human immunodeficiency virus epidemic is causing increases in the number of tuberculosis cases, particularly in Africa, although increases are also expected in Southeast Asia. In many industrialized countries, tuberculosis has recently failed to decline, and in eastern Europe and the former Soviet Union, cases and deaths are increasing. Drug resistance is a serious problem, especially in the United States. If worldwide control of tuberculosis does not improve, 90 million new cases and 30 million deaths are expected in the decade 1990 through 1999.