Conventional and molecular epidemiology of Tuberculosis in Manitoba

BACKGROUND: To describe the demographic and geographic distribution of tuberculosis (TB) in Manitoba, thus determining risk factors associated with clustering and higher incidence rates in distinct subpopulations. METHODS: Data from the Manitoba TB Registry was compiled to generate a database on 855 patients with tuberculosis and their contacts from 1992–1999. Recovered isolates of M. tuberculosis were typed by IS6110 restriction fragment length polymorphisms. Bivariate and multivariate logistic regression models were used to identify risk factors involved in clustering. RESULTS: A trend to clustering was observed among the Canadian-born treaty Aboriginal subgroup in contrast to the foreign-born. The dominant type, designated fingerprint type 1, accounts for 25.8% of total cases and 75.3% of treaty Aboriginal cases. Among type 1 patients residing in urban areas, 98.9% lived in Winnipeg. In rural areas, 92.8% lived on Aboriginal reserves. Statistical models revealed that significant risk factors for acquiring clustered tuberculosis are gender, age, ethnic origin and residence. Those at increased risk are: males (p < 0.05); those under age 65 (p < 0.01 for each age subgroup); treaty Aboriginals (p < 0.001), and those living on reserve land (p < 0.001). CONCLUSION: Molecular typing of isolates in conjunction with contact tracing data supports the notion of the largest ongoing transmission of a single strain of TB within the treaty-status population of Canada recorded to date. This data demonstrates the necessity of continued surveillance of countries with low prevalence of the disease in order to determine and target high-risk populations for concentrated prevention and control measures

Epidemiology of tuberculosis in Manitoba, 1992-1997

TuberculosisEpidemiologyTuberculosisHistoryTuberculoseEpidemiologieTuberculoseHistoireTuberculosis 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.

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Epidemiology, clinical features and outcomes of incident tuberculosis in children in Canada in 2013–2016: results of a national surveillance study

PurposeChildhood tuberculosis disease is difficult to diagnose and manage and is an under-recognised cause of morbidity and mortality. Reported data from Canada do not focus on childhood tuberculosis or capture key epidemiologic, clinical and microbiologic details. The purpose of this study was to assess demographics, presentation and clinical features of childhood tuberculosis in Canada.MethodsWe conducted prospective surveillance from 2013 to 2016 of over 2700 paediatricians plus vertical tuberculosis programmes for incident tuberculosis disease in children younger than 15 years in Canada using the Canadian Paediatric Surveillance Program (CPSP).ResultsIn total, 200 cases are included in this study. Tuberculosis was intrathoracic in 183 patients of whom 86% had exclusively intrathoracic involvement. Central nervous system tuberculosis occurred in 16 cases (8%). Fifty-one per cent of cases were hospitalised and 11 (5.5%) admitted to an intensive care unit. Adverse drug reactions were reported in 9% of cases. The source case, most often a first-degree relative, was known in 73% of cases. Fifty-eight per cent of reported cases were Canadian-born Indigenous children. Estimated study rates of reported cases (per 100 000 children per year) were 1.2 overall, 8.6 for all Indigenous children and 54.3 for Inuit children.ConclusionChildhood tuberculosis may cause significant morbidity and resource utilisation. Key geographies and groups have very high incidence rates. Elimination of childhood tuberculosis in Canada will require well-resourced community-based efforts that focus on these highest risk groups.</jats:sec