Contact investigation and isoniazid chemoprophylaxis in New York City, 1979-1987

The Bureau of Tuberculosis of the New York City Department of Health has carried out investigations of contacts to active cases of tuberculosis for many years. In addition, the Bureau has undertaken tuberculosis screening, with tuberculin testing and by radiography where indicated, of persons for employment purposes, school attendance, and for various other reasons. In 1969, the Bureau began providing isoniazid chemoprophylaxis; since then, more than 150,000 persons have been given isoniazid. Several isoniazid chemoprophylaxis effectiveness trials of chemoprophylaxis are achieved, the frequency of developing tuberculosis in one's lifetime would be reduced by 50%-70% by the time treatment is completed, according to several studies. On the basis of the beneficial results of these trials, the Bureau of Tuberculosis introduced the use of isoniazid chemoprophylaxis. This study was undertaken to assess the acceptability of isoniazid chemoprophylaxis and the success of contact investigation under both regular clinical conditions and uncontrolled conditions.