Tick-borne disease surveillance: Annual reports: Vector-borne disease surveillance in Canada
Vectors, such as ticks, spread diseases between humans or from animals to humans, usually by biting. Diseases spread by vectors are called vector-borne diseases. Find out how we monitor tick-borne diseases in Canada.
- Last updated: 2025-08-26
This page summarizes the latest annual data available regarding Lyme disease cases reported in Canada. We update this page annually, with data covering the previous year. It was last updated on March 20, 2025 with data between January 1, 2023 and December 31, 2023.
To view data regarding Lyme disease from previous years, please see the Expore the data tab. To better understand these data and this dashboard, please see the Technical notes tab.
For more details on tick-borne disease surveillance, please refer to our webpage on tick-borne diseases.
Key highlights from 2023
Human cases overview
- Almost double the cases of Lyme disease were reported in 2023 (n=4,785) than in 2022 (n=2,525).
- Overall, the national case count of Lyme disease has been trending upward since 2009 6.
- The incidence rate of Lyme disease in Canada in 2023 was 11.9 per 100,000 population. This is about double the incidence reported in 2022 (6.5 per 100,000 population) 7.
- This is partly due to a change in Nova Scotia’s provincial case definition in 2023 1. This year, more than six times the cases were reported from Nova Scotia (n=2,057) than in the previous year (n=326).
- Other reasons for the higher number of cases include greater human exposure to risk areas as tick habitat range expands with climate change.
Demographic characteristics
- Like previous years, cases were reported more commonly among males (57%) compared to females (43%) 8.
- A larger proportion of cases were reported among those aged 5-14 (9%) and 60-79 (37%) years than in other age groups.
- This may reflect behaviors associated with these age groups that increase risk of tick exposure, such as time spent outdoors, or less awareness of risk and preventive measures.
Seasonality
- Most cases reported an illness onset during the summer months of June (19%), July (40%), and August (16%).
- This is similar to findings from previous years, reflecting heightened tick activity and greater outdoor human activity in the Summer months.
- Summer activities associated with risk of tick bites include gardening and camping. Additional information about tick bite prevention is available.
Seasonality data table
| Episode month1 | Number of cases |
|---|---|
| January | 19 |
| February | 16 |
| March | 26 |
| April | 37 |
| May | 114 |
| June | 379 |
| July | 867 |
| August | 352 |
| September | 151 |
| October | 95 |
| November | 58 |
| December | 21 |
Geographic distribution
- Most cases were reported in Nova Scotia (43%), Ontario (39%) and Quebec (14%), consistent with previous years.
- Most cases in Ontario and Quebec occurred in the south-eastern and southern regions, respectively. Additional information about Lyme disease risk areas in Canada is available.
- Nova Scotia was the province with the highest incidence (194.7 per 100,000 population).
- More cases were reported than in the previous year in Manitoba (+53%) and New Brunswick (+71%).
Geographic distribution data table
| Geography | Number of cases |
|---|---|
| Canada | 4,785 |
| Yukon | 0 |
| British Columbia | 28 |
| Northwest Territories | 0 |
| Alberta | 20 |
| Saskatchewan | 3 |
| Manitoba | 58 |
| Ontario | 1,859 |
| Quebec | 652 |
| Nunavut | 0 |
| New Brunswick | 101 |
| Nova Scotia | 2,057 |
| Prince Edward Island | 5 |
| Newfoundland and Labrador | 2 |
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