Lyme Disease

Blacklegged Tick Surveillance

A person using a dragging method to capture ticks for identification.Toronto Public Health's tick surveillance program gathers information on the number of blacklegged ticks, their locations and the proportion of them that are infected with the bacteria that causes Lyme disease. This assists Toronto Public Health in assessing the risk of Lyme disease in Toronto. 

The tick surveillance program consists of ticks brought in by the public and ticks found by dragging. Ticks are identified to species. If they are found to be blacklegged ticks they can be sent to the National Microbiology Laboratory in Winnipeg for testing for the bacteria that causes Lyme disease. The testing process takes several weeks to months.

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. 

Active Tick Surveillance Map

Toronto Public Health's active tick surveillance map provides information on the locations where tick dragging has been conducted and dragging results. The map will be updated twice a year once tick dragging is completed in the spring and fall.  Because blacklegged ticks are known to be established at Rouge Valley, Morningside Park and Algonquin Island tick dragging will occur once a year in the fall at these locations to monitor numbers and infectivity rates.  Information regarding the active tick surveillance map is available in an accessible format.

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 then disappear.

Ticks are found in wooded or bushy areas with lots of leaves on the ground or where there are tall grasses.  Learn more on how to prevent Lyme disease when visiting these areas.


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