This study summarize the first 4 years (2009-2012) of national surveillance for Lyme Disease (LD) in Canada. LD surveillance data for 2009-2012 are analyzed to describe the early patterns (age, seasonality and presenting manifestations) of LD emergence in Canada and to compare against those reported in the US.

The study shows that: i) LD incidence is increasing in central and eastern Canada due to northwards expansion of the tick vector Ixodes scapularis; and ii) there is a lower proportion of cases presenting with early LD in Canada compared with the US suggesting lower awareness of early LD in Canada.