Toronto’s tick surveillance program monitors the number of blacklegged ticks, their locations and the number of them that carry the bacteria that causes Lyme disease (Borrelia burgdorferi). This information helps to determine the overall risk of Lyme disease in Toronto. Toronto has been engaged in active tick surveillance since 2013.
The tick surveillance program consists of ticks found by dragging.
Tick dragging is a process of collecting ticks in the environment and is done in the spring and fall when adult ticks are active. Dragging locations are selected based on suitable blacklegged tick habitat or a previous confirmed finding of a blacklegged tick. Blacklegged ticks may still be present in very low numbers at a site where none were found by tick dragging efforts. Ticks are found in wooded or bushy areas with lots of leaves on the ground or where there are tall grasses. As tick populations are expanding, it is possible that blacklegged ticks could be present outside the areas identified by Toronto Public Health. In addition, ticks can travel or migrate on the bodies of animals such as birds and therefore can be present in an area for a year in very low numbers and then disappear. The ticks are sent to the National Microbiology Laboratory in Winnipeg for confirmation of species and testing of adults and nymphs for Borrelia burgdorferi.