To the Editor.—
Among those given isoniazid (INH) chemoprophylaxis are many persons who have no lung disease but who are, nonetheless, at great risk from pulmonary tuberculosis. They are close contacts of newly discovered cases of tuberculosis, persons known to have recently become tuberculous infected (converted from negative to positive tuberculin reaction), and tuberculin reactors through the age of 20 years.1 Many are children; some are women of childbearing age. Their exposure to ionizing radiation, even to the small dosages associated with chest roentgenograms, should be commensurate with the results achieved.2 We conducted the following study to determine whether these tuberculin-positive persons need periodic chest roentgenograms while they take prophylactic treatment with INH.
Material and Methods.—
The population studied (Fig 1 and 2) consisted of 552 men, women, and children who had no evidence of lung disease when they accepted antituberculosis chemoprophylaxis at the New Orleans Tuberculosis Clinic