This review notes that, despite overall low rates of TB in Canada, marked regional variability occurs.
The authors suggest paying careful attention to epidemiologic risk factors such as recent immigration.
"Foreign-born children may arrive in Canada with latent -- dormant -- TB infection that activates after arrival. They, and the children of foreign-born parents, may acquire TB when an adult or adolescent in the home or extended family develops active and infectious TB."
Infection can also be acquired during visits to friends and relatives abroad, he noted.
Although the global incidence of TB is still much higher than in Canada -- 133 per 100,000 versus 4.6 per 100,000, respectively -- the latter "obscures marked regional variability," he and his colleagues explained.