Setting: A centre managing all tuberculosis (TB) cases in the population of the Calgary region in Canada.
Objective: To facilitate the diagnosis and management of TB by examining the distribution of TB by site of disease and the prevalence and pattern of drug-resistant Mycobacterium tuberculosis in a north American setting.
Design: A retrospective analysis of data collected at the time of diagnosis of all TB cases recorded during the 8-year period 1995-2002. Data collected included demographic information, site of disease, method of diagnosis and M. tuberculosis drug susceptibility.
Results: During the 8-year period, 435 cases of TB were diagnosed: 49% had exclusively extra-pulmonary disease. Lymph node disease (usually cervical) accounted for 44% of the extra-pulmonary cases. A culture of M. tuberculosis resistant to at least one first-line anti-tuberculosis drug was detected in 16% of the initial isolates. All of the resistant strains were found in foreign-born patients and resistance was more common in patients from Asia (19%) and in previously treated patients (26%).
Conclusion: Extra-pulmonary TB is common in the foreign-born population in the Calgary region, and this pattern may be more widespread than is realised. Drug-resistant strains of TB were more common in foreign-born and previously treated patients.