Chapter 1: Epidemiology of tuberculosis in Canada

Abstract

• The overall incidence rate of active tuberculosis (TB) disease in Canada is low and has remained unchanged in the last 10 years at around 4.6-5.1 individuals per 100,000 population, with males more affected than females. The rate in 2020 was 4.7 per 100,000 population. • Pronounced disparities in certain population subgroups and geographic regions persist. Foreign-born individuals and Canadian-born Indigenous peoples in particular continue to be disproportionately affected by TB. • The active TB disease incidence rate in Inuit communities has been the highest in Canada for the past two decades, peaking in 2012 at 251.6 individuals per 100,000 population, more than 51 times the overall Canadian incidence rate. In 2020, the incidence rate was 70.3 per 100,000 population, or 15 times the overall Canadian rate. • The rate of active TB disease among First Nations on-reserve populations has gradually decreased since 2009, and leveled off after 2017 at just under 20.0 per 100,000 population, or three times the Canadian incidence rate. Incidence rates among First Nations off-reserve populations have been lower, at about 10.0 per 100,000 population since 2013. • Métis have been less affected among Canadian-born Indigenous peoples, with active TB disease incidence rates that gradually decreased to levels below the overall Canadian rate since 2012, varying between 2.2 and 3.7 per 100,000 population. • Individuals born outside Canada constitute the largest proportion of people reported with active TB disease, with an incidence rate that has remained almost unchanged since 2005, at about 15.0 individuals per 100,000 population. • The Canadian-born, non-Indigenous population is the least affected, with an incidence rate that gradually decreased by 83.3%, from 1.2 per 100,000 population in 2001 to 0.2 per 100,000 population in 2020. • Between 2017 and 2020, 3.5% of individuals who had active TB disease and whose human immunodeficiency virus (HIV) status was known were HIV-positive. • In the last 20 years, on average, 12 TB-related deaths per year were reported in Canadian-born, non-Indigenous populations, compared to about 44 deaths annually for foreign-born populations. • Over the last 12 years, drug-resistant TB was isolated in 9.5% (n = 1,598) of people diagnosed with active TB disease and whose isolates were subjected to susceptibility testing. Of these, 83.2% (n = 1,329) had mono-resistance, primarily to isoniazid (INH) (n = 1,072) and pyrazinamide (PZA) (n = 225). Multidrug resistance (ie, resistance to INH and rifampin) accounted for 3.6% (n = 57), and extensively drug-resistance (ie, resistance to isoniazid and rifampin), plus any fluoroquinolone and at least 1 of 3 injectable second-line drugs (ie, amikacin, kanamycin or capreomycin), was rare and detected only 6 times.