Notifiable diseases online
Notifiable Diseases Online presents information based on data from the Canadian Notifiable Disease Surveillance System (CNDSS). Nationally notifiable diseases are communicable diseases that have been identified by the federal government and all provinces and territories as priorities for monitoring and control efforts. Through the CNDSS, provinces and territories voluntarily submit annual notifiable disease data, which are used to produce national disease counts and rates. The Notifiable disease charts can be used to explore trends in annual national counts and rates of reported cases of nationally notifiable diseases since 1924, where available.
The list of nationally notifiable diseases is revised periodically. Diseases that have been taken off the list can be reintroduced later if its status in Canada changes. Though in early years the decision to place a disease on the list relied on expert opinion, since 1987 these decisions have been based on federal/provincial/territorial consensus using set criteriaFootnote 1. The List of notifiable diseases provides the disease names and years in which they were considered notifiable.
Case definitions are the detailed descriptions used to identify cases of disease. Case definitions include the clinical signs and symptoms that define the appearance of the disease and the laboratory criteria for disease confirmation based on current national and international guidelines, literature review, and diagnostic laboratory practices and technology.
Exploring notifiable diseases data
- Cases reported only represent a portion of all the cases in the population. Cases may not be reported for the following reasons:
- Not all people will seek medical attention
- Reporting of diagnosed cases is not complete
- Diagnostic tests may result in a false negative
- Interpretation of the characteristics of a disease may vary. This is particularly true prior to 1990, when the first national case definitions were produced.
- Not all provinces or territories are able to report on all diseases in every year. Where a province or territory has not reported, it is noted in the limitations that appear with a disease selection. A province or territory not reporting does not necessarily mean that there have been no cases of the selected disease.
- Additional limitations specific to the disease or time period selected are listed under the requested table/graph and are important for interpretation of the data shown.
- Not all of the diseases that have ever been nationally notifiable are available in the charts. Diseases have not been included when the period of notifiability was short, the disease is no longer notifiable and was rare during its period of notifiability, or completeness and/or consistency of reporting was poor.
- Some diseases may fit into more than one of the indicated disease groups. However, each disease is presented in one group only.
- Age and sex breakdowns are available only from 1991 onwards.
- Only confirmed cases of disease are included.
- Due to periodic updates of the historical surveillance data, counts and rates for a particular disease and year may change over time.
Denominators used for rate calculations
Congenital and/or perinatal diseases:
- 1979 to 1990: Because live birth data were not available for this period, estimates were calculated using the proportion of low birth weight births in the given years from, “Low birth weight (less than 2,500 grams) and borderline viable birth weight-adjusted low birth weight (500 to less than 2,500 grams), by sex, Canada, provinces and territories, annual”. Source: Statistics Canada, CANSIM Table 102-4005 (Accessed 2013-08-01).
- 1991 to 2010: Live births from, “Live births, by month, Canada, provinces and territories, annual”. Source: Statistics Canada, CANSIM Table 102-4502 (Accessed 2015-05-19).
- 2011 to 2014: Live births from, “Estimates of births, deaths and marriages, Canada, provinces and territories, quarterly (number)”. Source: Statistics Canada, CANSIM Table 053-0001 (Accessed 2015-12-16).
- Please note that the number of births is final up to December 2011 and updated from January 2012 to December 2014.
All other diseases:
- 1924 to 2010: Final intercensal population estimates were used for calculating the appropriate denominators for rate calculations. The intercensal population estimates are final and remain stable over time. Source: Statistics Canada, Demography Division
- 2011 to 2014: Population estimates used to calculate denominators for the years 2011 to 2014 were as follows (Source: Statistics Canada, Demography Division):
- 2011: Final postcensal population estimate
- 2012-2013: Updated postcensal population estimates
- 2014: Preliminary postcensal population estimate
- Population estimates are subject to updates over time.
How to use Notifiable diseases online
This website provides data on nationally notifiable diseases including the counts and rates of reported cases, data limitations and disease descriptions. A graphical representation of the data is displayed based on the type of chart selected and on the parameters selected within each chart. The source data table, limitations of the data and descriptions for the selected notifiable disease(s) are also provided.
Careful consideration must be given when interpreting the data displayed in these charts and tables due to both limitations of the data and limitations of the chart functionality. When using the chart applications, it is also important to note that some diseases may be marked in red; in the accessible version of this site, these diseases will be marked with “N/A” in the tables. These are diseases which either were not nationally notifiable in the years(s) selected or for which data were not reported by any province/territory in the selected year(s), age group or sex. Note that lack of reporting does not necessarily mean that there were no cases.
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