Non-respiratory tuberculosis in Canada. Epidemiologic and bacteriologic features.

Of the total cases of tuberculosis reported in Canada between 1970-1974, approximately one-sixth (3671 cases) involved primarily non-respiratory organs. Common diagnostic entities were genitourinary tuberculosis (1516 cases), lymphadenitis (1083 cases), bone and joint tuberculosis (555 cases), gastrointestinal tuberculosis (155 cases) and meningitis (138 cases). The remainder (224 cases) involved a wide variety of organs. Between 1967 and 1977 the morbidity rates of most non-respiratory manifestations steadily declined, the decline in meningitis being particularly marked. In contrast, lymphadenitis did not decline to the same extent, reflecting changing immigration patterns. The major diagnostic entities differed in their age and sex patterns and in their contribution to total cases by birthplace and ethnic group. In particular, the preponderance of lymphadenitis in females, and in the Asian-born was striking. Mycobacterium bovis was isolated infrequently and bacillary resistance to antituberculosis drugs was also uncommon. In a substantial proportion of cases, active tuberculosis was present concurrently at another site, or there was historical or radiologic evidence of previous active tuberculosis. Despite this additional evidence, delay and failure of diagnosis were common. An increased clinical awareness of tuberculosis is required, particularly in view of the often enigmatic presentation of non-respiratory disease.