LD, caused by Borrelia burgdorferi in North America is transmitted to humans from wild animal reservoir hosts by Ixodes spp. ticks1 in their woodland habitats2. LD risk in Canada occurs where tick vectors are established in southern British Columbia (I. pacificus) and in southern parts of central and eastern Canada where I. scapularis is spreading from the United States (US)3. LD became nationally notifiable in Canada in 2009 and demographic data on human cases is submitted by provinces to Canadian Notifiable Disease Surveillance System of the Public Health Agency of Canada (PHAC). A Lyme Disease Enhanced Surveillance system was initiated by PHAC in 2010 to obtain more detailed data on LD cases. These surveillance systems aim to identify changing trends in LD incidence, the population at risk and the types of clinical disease in Canada. Surveillance data for 2009-2012 are analyzed to describe the early patterns of LD emergence in Canada. Patterns of LD cases (age, season of acquisition and presenting manifestations) were compared against those reported in the US.
Objective
To summarize the first 4 years (2009-2012) of national surveillance for LD in Canada and to conduct a preliminary comparison of presenting clinical manifestations in Canada and the United-States