Improving surveillance of the impact of influenza and its prevention in Canada.

The organization of Canada's provincial health care systems and the administrative databases that sustain them provide physicians, epidemiologists and public health officials with unique opportunities to improve surveillance of influenza and its prevention. These databases can be used to measure the impact of influenza on excess mortality, hospitalization and costs to the health care system. They can also be used to study the epidemiology of influenza vaccination practices. Studies using the administrative database for the province of Manitoba have established the epidemiological rationale for hospital-based vaccination and have evaluated the clinical effectiveness of influenza vaccination. As pneumococcal vaccination becomes widespread in Canada, provincial databases should also prove useful in assessing the impact of the pneumococcal infections and their prevention with pneumococcal vaccine.