Mosquito-borne disease surveillance: Explore the data: Vector-borne disease surveillance in Canada
Vectors, such as mosquitoes, 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 mosquito-borne diseases in Canada.
- Last updated: 2025-08-26
On this page
Maps
Notes
- The 2023 Saskatchewan WNV human data are preliminary and subject to change.
- Since 2014, Saskatchewan Public Health only follows up and collects data on WNV clinical - neuroinvasive disease cases.
- The map data is grouped according to natural breaks classification, based on Jenks' natural breaks algorithm. This method identifies the inherent natural groupings in the data by grouping similar values and maximizing differences between classes.
- WNV cases acquired outside of Canada are not included.
- Cases where travel was identified but travel location was unspecified were excluded from the analysis.
- Annual Incidence was calculated by dividing the number of confirmed and probable WNV disease cases by the population estimate for year in question, then multiplying by 100,000 to get the incidence per 100,000 population. WNV annual incidence = (disease cases/population estimate) * 100,000
- Average Annual incidence was calculated by summing the total number of WNV cases in the included date range and dividing this total by the number of years included in the range to calculate the average number of cases. Then the average number of cases was divided by the population estimate for the last year in the range and multiplied by 100 000 to get the incidence per 100 000 population. Average Annual Incidence = ((Total cases from all years/number of years included)/most recent population estimate) * 100 000
-
No notes available for the selected options.
Text description
Number of reported human West Nile virus cases by province
Number of reported human West Nile virus cases by province
Graphs
Notes
- The 2023 WNV data from Saskatchewan are preliminary and subject to change.
- Since 2014, Saskatchewan Public Health only follows up and collects data on WNV clinical - neuroinvasive disease cases.
- WNV cases acquired outside of Canada are not included.
- WNV cases with unknown disease classification are not included.
-
Annual Incidence was calculated by dividing the number of confirmed and probable WNV disease cases by the population estimate for the year in question, then multiplying by 100 000 to get the incidence per 100 000 population.
WNV annual incidence = (disease cases/population estimate) * 100 000
Cumulative Incidence was calculated by summing the total number of cases in the included date range, dividing by the population estimate for the last year in the range, then multiplying by 100 000 to get the incidence per 100 000 population.
Cumulative incidence = (the total cases from all included years/most recent population estimate) * 100 000
-
Average Annual Incidence was calculated by summing the total number of WNV cases in the included date range and dividing this total by the number of years included in the range to calculate the average number of cases. Then, the average number of cases was divided by the population estimate for the last year in the range and multiplied by 100 000 to get the incidence per 100 000 population.
Annual Incidence = ((Total cases from all years/number of years included)/most recent population estimate) * 100 000
-
Age and Sex Annual Incidence was calculated by grouping cases by both age and sex and dividing by the population estimate for that grouping of age and sex for the year in question.
Age-sex incidence = (age-sex disease cases/population estimate for age and sex group) * 100 000
-
Neuroinvasive Disease Average Annual Incidence by age group was calculated by summing the total number of neuroinvasive disease WNV cases in an age group in the included date range and dividing this total by the number of years included in the range to calculate the average number of cases. Then, the average number of cases was divided by the population estimate for the age group for the last year in the range and multiplied by 100 000 to get the incidence per 100 000 population.
Neuroinvasive Disease Average Annual Incidence = ((Total neuroinvasive cases in an age group/number of years included)/most recent population estimate for the age group) * 100 000
-
Cases where travel was identified but travel location was unspecified were excluded from the analysis.
-
No notes available for the selected options.
West Nile virus was not nationally notifiable until 2003; therefore, PHAC does not have line level data prior to 2003.
In Canada, WNV was first detected in mosquito pools and dead, wild birds in 2001, and in humans and horses in 2002.
Data are subject to change and reflect the most current data received from provinces and territories. The denominators used to calculate incidences were obtained from Statistics Canada, population estimates on July 1st.
Learn more about vector-borne diseases
- Date modified: