The outcome of contact procedures for tuberculosis in Edinburgh, Scotland 1982-1991

We have reviewed the records of 632 (80%) of the 788 index cases of tuberculosis notified in Edinburgh from 1982-1991 to assess the value of contact procedures for tuberculosis. Screening was by tuberculin testing and radiological follow-up for 6 months. Fifty (7.9%) of 632 notifications were detected by contact procedures and a further 35 contacts had recent infection qualifying for chemoprophylaxis. Tuberculosis was diagnosed at the first clinic visit in 38 (76%) cases and a further 11 (22%) were diagnosed at 3 months. Twenty-seven (54%) contacts with tuberculosis were in the 0-14 year age group. BCG vaccination offered 59% protection. Forty-two (84%) cases of tuberculosis were in contacts of sputum smear-positive respiratory index cases. Contact procedures continue to be effective in identifying new cases of tuberculosis in Edinburgh. Most cases occur in children who are close contacts of smear-positive respiratory index cases and are identified within 3 months of initiating screening. Screening of close contacts other than those of smear-positive respiratory disease is usually unnecessary.