Establishing priorities for national communicable disease surveillance.

The federal government has collected information on communicable diseases since 1924, under the legislative authority of the Statistics Canada Act and the Health Canada Act (1,2). Aggregate data on communicable diseases was initially collected and collated by The Dominion Bureau of Statistics (later changed to Statistics Canada), but this responsibility, with the exception of tuberculosis, was transferred to the Laboratory Centre for Disease Control (LCDC) in 1988. Responsibility for tuberculosis was subsequently transferred to the LCDC in 1995. Currently, information on communicable diseases under national surveillance is managed by the Division of Disease Surveillance within the Bureau of Infectious Diseases, LCDC. The delivery of health care and public health services is identified in the Canadian Constitution as a provincial power. The federal government has powers over the provision of safe food and the importation of communicable diseases, and has the power to assist in a crisis such as an infectious disease outbreak. Although communicable disease surveillance is carried out under provincial authority, coordination and monitoring occur at the federal level. Provincial and federal health authorities reach agreement on communicable disease surveillance by means of a joint committee called the Advisory Committee on Epidemiology (ACE) and its subcommittee on communicable diseases. The Division of Disease Surveillance is frequently asked why all infectious diseases of general interest are not nationally notifiable. First, disease surveillance requires money, time and energy for health care providers, local health units, provinces, territories or Health Canada to report and collect data on every communicable disease. Second, it requires considerable time and effort to make a disease nationally notifiable because every province and territory needs to go through the legislative or regulatory process of making the disease reportable within their jurisdictions. The process is managed by setting priorities to decide where to put the greatest effort. Criteria for priority setting should be explicit and measurable, and should minimize the influence of such factors as personal interest and political agendas. To the utmost degree possible, the criteria should be based on scientific evidence. Above all, “the challenge is to make the priority-setting process transparent and open to criticism and revision” (3). Before 1987, there was no mechanism in place to evaluate newly emerging diseases and compare them with the diseases that were being reported. Accordingly, in 1987, ACE established a subcommittee on communicable diseases to develop a systematic process to determine which communicable diseases should be monitored at the national level. The subcommittee asked which diseases should be routinely monitored, how should they be monitored and whether they should be monitored at all. These are important questions that have led to a priority setting exercise with the following objectives: to ensure national surveillance of major infectious diseases that threaten the health of Canadians; to support the development and evaluation of programs that are currently in place and those which have been proposed; to ensure the participation of Canada in the global surveillance of specific health threats; and to determine the best use of human and financial resources in the prevention and control of communicable diseases. The priority setting process involves several steps: establishing the criteria; subdividing each criterion into levels; assigning points to each level within each criterion; summing the points and assigning a total score to each disease; ranking the diseases from highest to lowest score; and determining a cut-off point that would allow the inclusion and exclusion of