A Century of Tuberculosis

Here are the facts: during the last 100 years in the thousands of years-long history of tuberculosis, we have benefited from unquestioned scientific and clinical progress; but at the same time we have witnessed a global increase in the number of victims and a worsening of the efficacy of control manifested by a rising prevalence of drug resistance in many countries. Today, tuberculosis is relatively easy to diagnose; when the right combination of medications is made available and taken by the patient, the disease can be cured more than 95% of the time; and in certain targeted populations, the manifestations of the disease can be attenuated by vaccination and even prevented by chemotherapy. Despite these remarkable achievements, the estimated number of new cases of tuberculosis in the world during each of the last several years has steadily increased: from 8.0 million in 1997 to 8.3 million in 2000, and is expected to reach 10.2 million in 2005 (1, 2). There are more people infected with Mycobacterium tuberculosis in the world this year than ever before, and from 1997 through 2000 the number of new cases of tuberculosis and the per capita incidence worldwide rose 1.8% per year and 0.4% per year, respectively (2). Although the overall global tuberculosis situation is deteriorating, it is actually improving in some countries. In the United States, for example, the incidence of newly reported cases of tuberculosis has fallen steadily since 1992 to its lowest level ever, and in 2002 (last report) was 5.2/100,000 population (3)—a stunning public health accomplishment. Such impressive progress, however, is found only in rich (industrialized) nations, although problems remain in many of their marginalized innercity communities; moreover, the reverse is occurring in many poor (developing) countries, which is where the great majority, 86%, of the world’s total population live. And not only are these destitute regions home to 95% of all the world’s cases of active tuberculosis and 98% of the nearly 2 million deaths from the disease each year, exactly the same countries are now being ravaged by the pandemic of human immunodeficiency virus (HIV) infection—the most powerful factor ever known to favor the development of tuberculosis (4). This historical review examines the century-long paradox of tuberculosis and illustrates an important point made by others (5): the conquest of tuberculosis by medical advances alone will never occur until the prevailing global inequities of wealth and health care are corrected.