Lyme Disease Emergence after Invasion of the Blacklegged Tick,Ixodes scapularis, Ontario, Canada, 2010–2016

Analysis of surveillance data for 2010-2016 in eastern Ontario, Canada, demonstrates the rapid northward spread of Ixodes scapularis ticks and Borrelia burgdorferi, followed by increasing human Lyme disease incidence. Most spread occurred during 2011-2013. Continued monitoring is essential to identify emerging risk areas in this region.