Epidemiology of tuberculosis in Manitoba, 1992-1997

Abstract

Tuberculosis in Manitoba is experiencing a declining trend, with a new tuberculosis rate between 1992 and 1997 of 9.2 per 100,000 person-year. Nevertheless, the value still significantly exceeds the 1995 national incidence rate of 6.5 per 100,000. The use of conventional and molecular epidemiology shows that between 1992 and 1997 there were 610 tuberculosis patients in Manitoba, 178 of which were non-treaty, 261 of which were treaty and 171 of which were foreign-born individuals. Among Manitoba tuberculosis cases with isolates, 194 different fingerprints types were identified. Thirty-six of the fingerprints occurred in cluster form while 158 occurred as unique fingerprints. The dominance of a single fingerprint (FP1) was found in 24.0% (115) of cases with isolates (Chapter 8, Table 3) and was observed to mainly infect Canadian-born patients (Chapter 8, Table 5). Clustered fingerprints indicate the existence of outbreaks and, in addition, it gives us an idea about the extent of secondary spread. Four different clustered fingerprints infected all three population subgroups, although it remains unknown why these fingerprints infect all population subgroups and others do not. Eight fingerprints in Manitoba infected foreign-born people only, while 5 infected treaty patients. Only one fingerprint was found exclusively in non-treaty individuals. (Abstract shortened by UMI.)