Public Health Ontario has once again posted their updated Lyme Disease Risk Areas map for 2018.  For comparison, you can still also access the 2017 map too, and you can see that once again (not surprisingly) the risk areas have expanded somewhat, including more of Eastern Ontario, as well as a few notable spots in York region and around Kenora in Northern Ontario.

  • The estimated risk areas are calculated as a 20 km radius from the centre of a location where blacklegged ticks were found through active drag sampling.
  • While low (but getting higher), there is a probability of encountering blacklegged ticks almost anywhere in the province.
  • Within estimated risk areas, blacklegged ticks are mainly found in woody and/or brushy areas.

For more information about how these maps are generated and how areas are selected for active tick dragging, download the complete pdf document here, or check out the PHO Lyme Disease website.

The Ontario Animal Health Network (OAHN) has also incorporated the updated map into the infographic “Ticks and Lyme Disease in Ontario: What’s the real risk?”  The graphic can be a useful tool for talking to clients about putting the risk of Lyme disease in context.