The Public Health Aspects of Tuberculosis

Most patients with tuberculosis are found because they present themselves for medical care. A high level of suspicion toward patients who are coughing and producing sputum and prompt examination of these patients are essential steps for the prevention of tuberculosis transmission. In addition to cough and expectoration, reasons for suspecting tuberculosis include symptoms and signs such as hemoptysis, weight loss, fatigue, night sweats, fever, pain, and adenopathy; radiographic findings compatible with pulmonary tuberculosis; a significant reaction to the tuberculin skin test; and a history of exposure to another person with infectious tuberculosis. Suspicion should be heightened when these findings are associated with certain clinical situations that may increase the risk of developing tuberculosis. Examples of these special circumstances include prolonged treatment with corticosteroids or immunosuppressive drugs or both, chronic renal failure and dialysis, ileal bypass surgery or gastrectomy, diabetes mellitus, silicosis, and hematologic and reticuloendothelial disorders such as leukemias and lymphomas. Since symptoms are not specific for tuberculosis, it also helps to have demographic and epidemiologic knowledge of which persons in general are most apt to have tuberculosis, and specific knowledge of the tuberculosis situation in the local community. Although tuberculosis occurs in all segments of the population, case rates are higher in older persons than in younger persons, in males than in females, in foreign-born than native-born persons, and in races other than white. The vast majority of tuberculosis cases in the United States arises from a pool of 10 to 15 million persons with dormant tuberculous infection. The only detectable sign of infection in most of these persons is the ability to react significantly to a tuberculin skin test. Unless treated, these persons carry a lifelong risk of potentially developing disease and transmitting it to others.