Chemotherapy for the tuberculin converter: results of a survey of attitudes among 424 tuberculosis hospitals in the United States.

Persons whose reaction to tuberculin has changed from negative to positive are known as tuberculin converters. There is widespread interest in chemotherapy for tuberculin converters as a means of preventing the development of clinical tuberculosis. Drug therapy of this kind is referred to as chemoprophylaxis. The effectiveness of chemoprophylaxis is thought to be greatest when offered to those whose tuberculin reactions are known to have changed from negative to positive within the previous year. Robinson, Meyer and Middlebrook1 were the first to report a pronounced decrease in the skin hypersensitivity of four infants to tuberculin during treatment with isoniazid. In each instance the reaction became negative to old tuberculin in a dilution of 1 :100. Though few in number, their series of cases was of considerable interest to all who are intrigued with the idea of treating tuberculous infection in its earliest recognizable stage. So far, results have not been reported of the studies that are being made on a large scale by the United States Public Health Service.