Pulmonary Tuberculosis in Contacts: A Ten Year Survey

¹ The Chest Department, Ruchill Hospital.

The incidence of tuberculosis in 664 household contacts of 155 people discovered to have active pulmonary tuberculosis in 1948 was investigated. Over a ten-year period 81 (12 per cent) of the 664 contacts developed active tuberculosis; eight (1.2 per cent) non-respiratory tuberculosis, 12 (1.8 per cent) childhood-type primary pulmonary tuberculosis necessitating hospital treatment, and 61 (9.2 per cent) adult-type pulmonary tuberculosis.

Of the 61 cases of adult pulmonary tuberculosis, about one-third (22) were discovered in the first year, about one-half (32) in the first two years, and about three-quarters (46) in the first five years. In women contacts aged less than 25 years in 1948, all the disease detected was found in the first five years, but in men contacts and in women contacts aged 25 to 44 years in 1948, disease continued to appear throughout the ten-year period. Of 79 women contacts aged more than 44 years in 1948, none developed disease. These findings suggest that women contacts aged less than 25 years should be supervised for five years, that women contacts aged more than 44 years need no supervision beyond an initial x-ray film, and that other classes of contacts should be supervised for ten years at least.

Long-term supervision still presents many practical difficulties, and at best can only limit and not prevent dissemination of infection. Chemoprophylaxis for contacts also presents difficulties, but it is suggested that its potential advantages seem so great that a trial is indicated.