Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Nov 1;44(11):290-296.
doi: 10.14745/ccdr.v44i11a04.

Tuberculosis drug resistance in Canada: 2017

M LaFreniere  1 , H Hussain  1   2 , J Vachon  1
Affiliations

Tuberculosis drug resistance in Canada: 2017

M LaFreniere et al. Can Commun Dis Rep. .

Abstract

Background: Drug-resistant tuberculosis (TB) is a global public health issue. To monitor this in Canada, surveillance systems have been in place for the last 20 years.

Objective: To describe drug resistance patterns among TB isolates in Canada in 2017 by type of resistance as well as geographic location, demographic data and origin and to compare current data to those of the previous 10 years.

Methods: Data were derived and analyzed from two sources. The Canadian Tuberculosis Laboratory Surveillance System (CTBLSS) is an isolate-based laboratory surveillance system and was used to obtain information on the results of drug susceptibility testing (DST) as well as province or territory, sex and age of the individual from which the sample originated. The Canadian Tuberculosis Reporting System (CTBRS) is a case-based surveillance system with information on active and retreatment TB cases in Canada and was used to derive origin data, which is defined as either foreign-born, Canadian-born Indigenous or Canadian-born non-Indigenous. Analysis was descriptive and compared with data from these two sources for 2007-2016.

Results: In 2017, 1,515 TB isolates were tested for resistance to anti-TB drugs, with 123 (8.1%) demonstrating resistance to any first-line anti-TB drug. Of these, 103 were monoresistant, six were polyresistant and 14 were multidrug-resistant tuberculosis (MDR-TB). No extensively drug-resistant tuberculosis (XDR-TB) isolates were reported. Drug resistance was reported in seven provinces/territories (British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec and New Brunswick). There were 63 isolates from females with drug resistance (9.5%) and 60 isolates from males with drug resistance (7.0%). Drug resistance was found in a greater percentage of isolates among those aged 25-34 (n=29, 23.6%). By origin, 1,072 (11%) foreign-born TB cases reported between 2005 and 2015 were drug-resistant. Among the Canadian-born non-Indigenous and Canadian-born Indigenous TB cases, 143 (9%) and 54 (2%) were drug-resistant, respectively. Compared with previous years, the number of isolates tested increased slightly (from 1,267 to 1,515); however, there was a decrease in the percentage of isolates with reported drug resistance (from 10.5% in 2007 to 8.1% in 2017).

Conclusion: In 2017, TB drug resistance rates remained low in Canada.

Keywords: ethambutol; extensively drug-resistant tuberculosis; isolates; isoniazid; multidrug-resistant tuberculosis; pyrazinamide; resistance; rifampin; surveillance; tuberculosis.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest: None.Funding: This work was supported by the Public Health Agency of Canada as part of its core mandate.

Figures

Figure 1
Figure 1. Number of tuberculosis isolates tested for anti-TB drug susceptibility and results, Canada, 2017
Abbreviations: BCG, Bacillus Calmette–Guérin; EMB, ethambutol; INH, isoniazid; MDR-TB, multidrug-resistant tuberculosis; MTB, Mycobacterium tuberculosis; M. bovis, Mycobacterium bovis; PZA, pyrazinamide; RMP, rifampin; TB, tuberculosis
Figure 2
Figure 2. Proportion of tuberculosis isolates with reported drug resistance by drug resistance pattern, Canada, 2007–2017
Abbreviations: MDR-TB, multidrug-resistant tuberculosis; XDR-TB, extensively multidrug-resistant tuberculosis
Figure 3
Figure 3. Proportion (%) of isolates demonstrating any anti-TB drug resistance by province/territory, Canada, 2017
Abbreviation: TB, tuberculosis
Figure 4
Figure 4. Percentage of tuberculosis isolates with reported drug resistance by sex and resistance pattern, Canada, 2007–2017
Abbreviations: MDR-TB, multidrug-resistant tuberculosis
Figure 5
Figure 5. Percentage of tuberculosis isolates with reported drug resistance, by age group and resistance pattern, Canada, 2017
Abbreviations: MDR-TB, multidrug-resistant tuberculosis; <, less than; +, and up
See this image and copyright information in PMC

References

    1. World Health Organization. Global tuberculosis report 2017. Geneva: World Health Organization; 2017. http://www.who.int/tb/publications/2017/en/
    1. Vachon J, Gallant V, Siu W. Tuberculosis in Canada, 2016. Can Commun Dis Rep 2018;44(3/4):75–81. 10.14745/ccdr.v44i34a01 - DOI - PMC - PubMed
    1. Gallant V, Vachon J, Siu W. Tuberculosis drug resistance in Canada: 2006-2016. Can Commun Dis Rep 2017. Nov;43(11):236–41. 10.14745/ccdr.v43i11a05 - DOI - PMC - PubMed
    1. Menzies D, Wong T, editors. Canadian tuberculosis standards. 7th ed. Canadian Thoracic Society, Canadian Lung Association, Public Health Agency of Canada; 2014. https://www.canada.ca/en/public-health/services/infectious-diseases/cana...
    1. Public Health Agency of Canada. Tuberculosis in Canada 2012. Ottawa (Canada): Minister of Public Works and Government Services Canada; 2015. https://www.canada.ca/content/dam/phac-aspc/migration/phac-aspc/tbpc-lat...