Tick-borne disease surveillance: Technical notes: Vector-borne disease surveillance in Canada

On this page

• Human Surveillance
• Data definitions and notes
• Data limitations
• Acronyms
• Acknowledgements and citation
• Related links

The Public Health Agency of Canada (PHAC) works with provincial and territorial partners to monitor the number of people with tick-borne disease in Canada.

Tick-borne diseases that are significant to public health are nationally notifiable in Canada. This means provinces and territories voluntarily report cases to PHAC. A national case definition is developed for each nationally notifiable disease.

All provinces and territories report cases to PHAC through the Canadian Notifiable Disease Surveillance System (CNDSS). Information collected through CNDSS includes age, sex, and case classification (probable or confirmed).

General definitions

Vectors
Living organisms, most commonly invertebrates such as mosquitoes, ticks and flies, that can carry and spread infectious diseases between animals and humans.

Vector-borne diseases
Infectious diseases caused by pathogens such as parasites, viruses or bacteria, which are spread between animals and humans by infected vectors, usually by biting.

Zoonotic diseases (zoonoses)
Infectious diseases that are spread between animals and humans in various ways such as direct contact, indirect contact or through vectors.

Human surveillance

Lyme disease is the most common tick-borne disease reported in Canada. Lyme is a nationally notifiable disease. For a case to be reported, it must meet the national case definition for Lyme disease. Lyme disease has been nationally notifiable in Canada since 2009.

In 2011, the Lyme Disease Enhanced Surveillance (LDES) system was developed and implemented. Participating regions use the system to report additional information not collected by the CNDSS. In the last year, eight provinces reported information. Additional information may include:

• geographical location of infection
• clinical features
• laboratory results

The LDES complies with the regulations of the federal, provincial, and territorial Multi-Lateral Information Sharing Agreement.

Provincial and territorial public health authorities report Lyme disease cases and send annual data to PHAC each summer.

Data definitions and notes

Human data definitions

Case classification

Cases are classified as probable or confirmed based on the national case definition for Lyme disease.

Reported illness onset

Reported illness onset is the month the first symptoms are seen for locally acquired cases.

Data notes

• The Lyme Disease Enhanced Surveillance system is passive, as it relies on health authorities to report cases.
• Travel-related cases that were probably acquired outside of Canada are excluded from analyses of seasonal trends. They are included in all other analyses.

Data limitations

• The annual number of tick-borne disease cases can fluctuate for different reasons including:
• underreporting
• public health prevention efforts
• variations in weather affecting tick activity each year
• changes in healthcare-seeking behaviors or outdoor activity levels due to factors such as the COVID-19 pandemic
• Local, provincial and territorial public health authorities use varying levels of surveillance and procedures of investigation. This contributes to a variation between provinces in the proportion of cases classified as confirmed or probable.
• Data on this dashboard may not match surveillance data on provincial and territorial disease reporting websites. Provinces and territories may update surveillance data on their sites. These updates may not be reflected in this dashboard, particularly for historical data.

Acronyms

CNDSS

Canadian Notifiable Disease Surveillance System

LDES

Lyme Disease Enhanced Surveillance

PHAC

Public Health Agency of Canada

Acknowledgements and citation

This dashboard is a collaboration between local, provincial and territorial public health data providers.

Suggested citation

Vector-borne disease surveillance in Canada. Ottawa, Canada: Public Health Agency of Canada. https://health-infobase.canada.ca/zoonoses/tick

Related links

Government of Canada

• Lyme Disease
• Multi-lateral information sharing agreement

Provincial, territorial and international surveillance

• British Columbia – Lyme Disease
• Alberta – Lyme Disease
• Saskatchewan – Lyme Disease
• Manitoba – Lyme Disease
• Ontario – Lyme Disease
• Québec – Lyme Disease
• Nova Scotia – Lyme Disease
• New Brunswick – Lyme Disease
• Prince Edward Island – Lyme Disease
• Newfoundland and Labrador – Lyme Disease
• U.S. Centers for Disease Control and Prevention – Lyme Disease
• European Centre for Disease Prevention and Control – Lyme Disease