Tuberculosis drug resistance in Canada: 2018

Marie LaFreniere; Demy Dam; Lori Strudwick; Sarah McDermott

doi:10.14745/ccdr.v46i01a02

Tuberculosis drug resistance in Canada: 2018

Can Commun Dis Rep. 2020 Jan 2;46(1):9-15. doi: 10.14745/ccdr.v46i01a02.

Authors

Marie LaFreniere¹, Demy Dam^{1

2

3}, Lori Strudwick⁴, Sarah McDermott¹

Affiliations

¹ Centre for Communicable Disease and Infection Control, Public Health Agency of Canada, Ottawa, ON.
² Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC.
³ Canadian Tuberculosis Laboratory Technical Network (Note: Network members are noted at the end of the paper).
⁴ Government of Yukon, Health and Social Services, Yukon Communicable Disease Control, Whitehorse, YT.

Abstract

Background: Drug-resistant tuberculosis (TB) is a public health issue of global importance that poses a threat to TB control efforts. Canada conducts nationwide surveillance to monitor emerging drug resistance trends and document progress towards reaching the goal of TB elimination.

Objective: To describe TB drug resistance trends across Canada from 2008-2018, with a focus on 2018, by drug resistance, geographic and demographic patterns.

Methods: TB drug resistance data are captured through two independent surveillance systems managed by the Public Health Agency of Canada: Canadian Tuberculosis Laboratory Surveillance System (CTBLSS) and the Canadian Tuberculosis Reporting System (CTBRS). Data from these systems were analyzed and descriptive statistics were reported by resistance profile, place of residence (province), age groups, sex and country of birth.

Results: In 2018, 1,459 TB isolates underwent drug susceptibility testing, a 4.3% decrease from 2017. Resistance to any first-line drug was reported in 148 isolates (10.1%), compared to 123 (8.1%) in 2017. Of these, 121 were monoresistant, five were polyresistant, 21 were multidrug-resistant tuberculosis (MDR-TB) and one was extensively drug-resistant TB (XDR-TB). Drug resistance was reported in all provinces and territories except Prince Edward Island, Northwest Territories and Yukon. Among individuals younger than 15 years, very little TB drug resistance was detected. Among individuals aged 15 years and older, the distribution of TB drug resistance varied with no discernable trends. The proportion of drug resistance was slightly higher in females than in males. By origin, 10.7% of foreign-born TB cases reported between 2006 and 2016 were drug-resistant. Among the Canadian-born non-Indigenous cases, 9.3% were drug resistant; among Canadian-born Indigenous, 2.4% were drug resistant.

Conclusion: In 2018, the proportion of isolates with TB drug resistance in Canada remained low and below global averages, with stable drug resistance, both geographically and demographically.

Keywords: Canada; drug resistance; surveillance; tuberculosis.