The prevention of tuberculosis requires that the public be protected against droplet infection originating in a patient with tuberculosis. This, in turn, requires that all persons with a positive sputum be identified and isolated from others until they become noninfectious. Thus basically, the prevention of new cases of tuberculosis depends primarily on case finding, isolation, and continued surveillance of patients with active disease.
At one time there was in the United States a problem with bovine tuberculosis. To a limited extent, bovine tuberculosis is still seen, but an active program of case finding among cattle (using the tuberculin test) and destruction of infected animals, combined with the fact that practically all milk today is pasteurized, has made this method of infection a rarity.
In some parts of the world great reliance is placed on prevention by use of the BCG vaccine. Indeed, in some of the developing nations, BCG vaccination may be the only feasible method of tuberculosis control. In this country, BCG vaccination has been used only in high-risk groups (such as medical students and student nurses) and in groups such as American^ Indians and Eskimos with a high prevalence of the disease. /
There has been some experience with chemotherapy (isoniazid) used prophylactically. In a study carried out in Alaska, it was found that chemotherapy prevented 70 percent of the cases that might otherwise have occurred. This approach is practicable only among populations with a high prevalence of tuberculosis.
Progress in Tuberculosis Control
Considerable progress is being made toward the eradication of tuberculosis as a community health problem. The mortality rate today is approximately one twentieth what it was in 1900. The annual incidence of new cases is also falling, but at a slower rate, and is now much lower than the 1900 rate.