Tuberculosis in Canada 2007

Table of Contents

• EXECUTIVE SUMMARY
• INTRODUCTION
• RESULTS
  • SECTION I – 2007 CASE REPORTING
    • National trends
    • Geographic distribution
    • Sex and age group distribution
    • Birthplace distribution
    • Diagnostic details
    • Case detection
    • Deaths
    • HIV status
    • Patterns of drug resistance
  • SECTION II – 2006 TREATMENT OUTCOMES
    • Acquired drug resistance
  • SECTION III – MEASURING PROGRESS TOWARDS NATIONAL TARGETS
• CONCLUSION
• APPENDICES
  • Appendix I Data tables: 2007
  • Appendix II Technical notes
  • Appendix III Population estimates: 2007
  • Appendix IV WHO estimated incidence of TB, 22 high-burden countries: 2007
  • Appendix V STOP-TB partnership TB epidemiological regions and member countries
  • Appendix VI WHO reporting form for 2007
  • Appendix VII Canada – Case and treatment outcome reporting forms
  • Appendix VIII The Canadian Tuberculosis Committee 2009
• FIGURES
  • Figure 1 Tuberculosis incidence and mortality rates – Canada: 1924-2007
  • Figure 2 Tuberculosis cases and incidence rates – Canada: 1987-2007
  • Figure 3 Tuberculosis incidence rate by province/territory as compared with national rate (4.7 per 100,000): 2007
  • Figure 4 Tuberculosis incidence rate by sex – Canada: 1987-2007
  • Figure 5 Tuberculosis incidence rate by age group – Canada: 2007
  • Figure 6 Tuberculosis incidence rate by age group and sex – Canada: 2007
  • Figure 7 Percentage of tuberculosis cases by origin – Canada: 1987-2007
  • Figure 8 Number of tuberculosis cases by origin – Canada: 1987-2007
  • Figure 9 Tuberculosis incidence rate by origin – Canada: 1997-2007
  • Figure 10 Proportion of tuberculosis cases by age group and origin – Canada: 2007
  • Figure 11 Percentage of foreign-born tuberculosis cases by STOP-TB Partnership/WHO TB epidemiological regions – Canada: 1997-2007
  • Figure 12 Origin of tuberculosis cases and overall incidence rate – provinces/territories: 2007
  • Figure 13 Tuberculosis cases by main diagnostic site and origin – Canada: 2007
  • Figure 14 Pulmonary sputum smear positive tuberculosis cases – Canada: 1997-2007
  • Figure 15 Percentage of tuberculosis cases by HIV status – Canada: 1997-2007
  • Figure 16 Treatment outcome status of tuberculosis cases by major mode of treatment – 2006
• TABLES
  • Table A Incidence rate of tuberculosis in Canada: 1997-2007
  • Table B Ranked tuberculosis incidence in Canada – provinces/territories: 2007
  • Table C Comparison of the reported foreign-born tuberculosis incidence rate in Canada by STOP-TB Partnership/WHO TB epidemiological regions of birth (per 100,000 population) with WHO estimated tuberculosis incidence rate in the respective region
  • Table D Percentage of tuberculosis cases in Canada by origin – provinces/territories: 2007
  • Table E Treatment outcome of laboratory confirmed pulmonary cases - Canada: 1998-2005
  • Table F Average rate of change in the number of cases and in incidence rate for new and relapsed TB cases in Canada: 1997–2007
  • Table G ICD9 and ICD10 codes by diagnostic classification

Executive Summary

In total, 1,548 new active and relapsed tuberculosis (TB) cases (a rate of 4.7 per 100,000 population) were reported to the Canadian Tuberculosis Reporting System (CTBRS) in 2007. Compared with 2006, both the number of cases reported and the incidence rate decreased, representing a 6.3% and 7.3% change, respectively. The TB incidence rate in 2007 was the lowest recorded since data collection began in Canada in 1924.

The three most populous provinces (British Columbia, Ontario and Quebec), which collectively made up 75% of Canada’s population in 2007 accounted for 75% of the total number of reported cases. The highest incidence rate, 99.2 per 100,000 population was reported in Nunavut. For New Brunswick and Nova Scotia the rate was less than 1 per 100,000 population. For Prince Edward Island, no TB cases were reported.

Individuals between the ages of 35 and 44 years of age made up the largest number of reported cases, representing 18% of the total.  The age-specific rate of 10.1 per 100,000 for those in the 75 years plus age group was the highest rate recorded for all age groups. In the 65-74 year age group, the rate continued to remain higher relative to the younger age groups.

In 2007, foreign-born cases continued to represent the greatest percentage of the overall case count when compared with the Canadian-born non-Aboriginal and Canadian-born Aboriginal populations.  A total of 1,042 TB cases were reported among the foreign-born, representing 67% of all cases. A total of 170 cases (11% of the total) were in the Canadian-born non-Aboriginal population and 307 cases (20% of the total) were diagnosed in the Canadian-born Aboriginal population.

Pulmonary TB, including TB of the lungs and conducting airways was the most frequently reported diagnostic site, accounting for 65% of reported cases in 2007 followed by TB of the peripheral lymph nodes, which accounted for 13% of the reported cases.

Data on HIV status continues to be underreported at the national level. Of the 1,548 cases reported, 447 cases (29%) had an HIV test result reported (Figure 15). Across the provinces and territories, the percentage of cases for which HIV status was reported ranged from 0% to 96% of reported cases.

Of the 1,548 cases reported in 2007, 1,231 cases were culture positive.  Of these, resistance information was available for 1,188 cases.  Ninety-one percent of these showed no resistance to first-line anti-TB drugs (isoniazid, rifampin, ethambutol or pyrazinamide)¹ , 8% percent were resistant to one drug and the remaining 1% showed patterns of resistance to two or more drugs prescribed.

For the 111 cases that were resistant to at least one drug, 85% were monoresistant with resistance to isoniazid accounting for 87% of all such cases.  Nine percent were multidrug-resistant (MDR), defined as resistance to at least isoniazid and rifampin.  One case was identified as being extensively drug-resistant (XDR).

Of the 143 deaths, TB was reported as the underlying cause of death for 23 cases (16%). TB contributed to death, but was not the underlying cause for 68 cases (48%). Cause of death was not reported for 7 cases.

As of June 30, 2008, 124 (8%) of the 1,548 cases diagnosed in 2007 were reported to have died before or during treatment. Of these, TB was reported as the underlying cause of death for 28 cases (23%). TB contributed to death, but was not the underlying cause for 56 cases (45%).  Cause of death was not reported for 3 cases. 

The majority of individuals placed on TB drug therapy in Canada received treatment as per the Canadian Tuberculosis Standards².  Of the cases where the treatment final regime was reported over 80% of these cases received three or more anti-tuberculosis drugs.
For the 1,652 cases reported in 2006, 1,541 (93%) had outcome data (partial and complete) available. Of these cases, 1,270 (82%) were reported as cured or had completed treatment, 143 (9%) died before or during treatment, 29 (2%) transferred out of Canada, 35 (2%) absconded before completion of 80% of treatment and treatment was ongoing for 46 (3%) cases.  For 129 (8%) cases, treatment outcome was not recorded or was recorded as other.

Although the total number of reported cases of TB in Canada has shown a general decrease over the past decade, this decrease is mostly a reflection of a decreasing number of cases in the Canadian-born non-Aboriginal population.  Between 1997 and 2007 there was an average annual decrease of 8% in the number of cases reported in the Canadian-born non-Aboriginal population.  The number of cases in the foreign-born population also decreased annually but only by an average of 2%. In the Canadian-born Aboriginal population, however, the number of cases increased by an average of 2% per year over the past decade.

Introduction

The 2007 Tuberculosis in Canada annual report is a publication of Tuberculosis Prevention and Control (TBPC), Public Health Agency of Canada (PHAC). Collection of statistics on tuberculosis in Canada started in 1924 and TBPC stores and maintains copies of all these historical reports. In 1994, responsibility for the Canadian Tuberculosis Reporting System (CTBRS) was transferred from Statistics Canada to Health Canada. In September 2004, TBPC became part of the PHAC and assumed responsibility for the annual reporting. Records of all new active and relapsed tuberculosis cases come to TBPC from the ten provinces and three territories on an annual basis.

This report contains the overall TB case counts and incidence rates as well as data on selected demographic and clinical characteristics. This report describes information on the following for TB cases:

• province/territory
• sex
• age
• birthplace
• new and relapsed cases
• main diagnostic site
• bacterial status
• method of detection
• immigration status
• HIV status
• risk factors/markers for disease

• patterns of drug resistance
• treatment outcomes
• drug regimens

Appendices to the report include data tables (Appendix I), technical notes (Appendix II), population estimates for 2007 (Appendix III) and the World Health Organization (WHO) estimated incidence of TB in the 22 high burden countries, 2007 (Appendix IV). Further appendices include the WHO TB epidemiological regions and the member countries (Appendix V), the WHO reporting form for 2007 cases (Appendix VI), Canadian case and treatment outcome reporting forms (Appendix VII) and the members of the Canadian Tuberculosis Committee (Appendix VIII).

These annual reports have undergone and will continue to undergo revisions in format and content from year to year. The goal is to continue to adapt and improve this publication in response to changes in the epidemiology and clinical management of TB. Comments on the content and/or format of this document are always welcome.

MISSION:

Our mission is to promote and protect the health of Canadians through leadership, partnership, innovation and action in public health.
- Public Health Agency of Canada

HOW TO REACH US

For more information, copies of this report or other related reports please contact:

Tuberculosis Prevention and Control
Community Acquired Infections Division
Centre for Communicable Diseases and Infection Control
Infectious Disease and Emergency Preparedness Branch
Public Health Agency of Canada
100 Eglantine Driveway, Health Canada Building
A.L. 0603B, Tunney's Pasture
Ottawa, ON K1A 0K9
Telephone: (613) 941-0238
Facsimile: (613) 946-3902
EMAIL: TB.1@phac-aspc.gc.ca

Tuberculosis in Canada 2007
Is available on the Internet at the following address
http://www.publichealth.gc.ca/tuberculosis

Également disponible en français sous le titre :
La Tuberculose au Canada 2007

This publication can be made available on request on diskette, large print, audio-cassette and braille.

This report was prepared by:

 

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