Map of Simcoe Muskoka


Passive Tick Surveillance

Key Messages
Tick Submissions
Technical Notes

Key Messages

  • During the COVID-19 Pandemic, Simcoe Muskoka District Health Unit (SMDHU) stopped accepting tick submissions from the public, to maintain public health measures to stop the spread of COVID-19. Instead, individuals were encouraged to use to identify ticks they found.
  • Effective September 20, 2021, the National Microbiology Laboratory (NML) will no longer accept blacklegged ticks for bacterial testing for Borrelia burgdorferi as part of the passive tick surveillance program. Passive tick surveillance will be supported by citizen science initiatives, such as eTick, where the public can upload pictures of ticks for identification.
  • We are currently exploring new data sources to continue to share data on local tick populations.
  • An increasing number of ticks have been submitted to the health unit over recent years.
  • The proportion of these ticks that are Ixodes scapularis (blacklegged ticks) and the proportion of those blacklegged ticks that are locally acquired has been growing from 2007 to 2019.
  • A growing number of the blacklegged ticks submitted to the health unit are testing positive for Borrelia burgdorferi, the bacteria which causes Lyme disease.

Tick Submissions

  • In 2019, 12 locally acquired Ixodes scapularis (blacklegged ticks) tested positive for Borellia burgdorferi.
  • From 2007 to 2019, 52% of locally acquired ticks submitted were blacklegged ticks, between 0% in 2008 to 71% in 2019. This suggests that blacklegged ticks continue to spread in our local environment.
  • From 2007 to 2019, 1,257 ticks were submitted to the Simcoe Muskoka District Health Unit for testing.
  • Half (49%) of the ticks submitted to the health unit from 2007 to 2019 were blacklegged ticks.
  • Three-quarters (76%) of the blacklegged ticks received in this period were locally acquired, meaning they resulted from outdoor activity in the Simcoe Muskoka region.


In 2019, 12 locally acquired blacklegged ticks submitted to the health unit tested positive for Borrelia burgdorferi, the pathogen which causes Lyme disease, this is an increase from 3 in 2018 and 8 in 2017. From 2014 to 2019, there were an additional 25 black legged ticks submitted to the health that tested positive for B. burgdorferi: 21 acquired in other regions in Ontario, one in the United States and three acquired in unknown locations.


Technical Notes

When people find a tick on themselves or on other people, they are encouraged to take a picture and upload the photo to for identification and to contact their healthcare provider to help assess their risk of Lyme disease.

Ticks are no longer being collected by the health unit as part of a passive tick surveillance program, and ticks are no longer being tested for Borrelia burgdorferi, the bacteria that causes Lyme disease in humans.

An endemic area is defined as an area in which a reproducing population of Ixodes scapularis or Ixodes pacificus tick vectors is known to occur, which has been demonstrated by molecular methods to support transmission of B. burgdorferi at that site (source: Public Health Ontario Lyme Disease Case Definition).

A risk area is defined as a location where at least one blacklegged tick was found during three person-hours of drag sampling at a location, between May and October. Locations for active tick drag sampling are determined based on information from passive tick surveillance and suitable conditions to support populations of blacklegged ticks.

Further Reading

For more information about ticks and Lyme Disease:

Page Last Modified: September 20, 2021.