Modelling of Pandemic Influenza in Canada: Predicted Burden and Hospital-Resource Adequacy

Abstract

For centuries, pandemic influenza has emerged at irregular and unpredictable intervals to cause widespread illness, hospitalization and death. Uncertainty surrounding the timing and severity of future influenza pandemics present challenges for preparedness and response efforts. The objective of this dissertation is to advance pandemic influenza knowledge and preparedness, through a series of interrelated articles that address the follow research questions: 1. What are the likely consequences of a pandemic flu event in Canada? 2. What do mathematical models tell us about preparing for such an event? 3. What is the best way to mitigate the consequences of an influenza pandemic? Six articles were prepared for submission in scientific, peer-reviewed journals. The first is a historical review of the burden of pandemic influenza. The second and third are systematic reviews of the effectiveness of interventions to interrupt pandemic influenza transmission. The fourth and fifth are research papers presenting a novel mathematical model, assessing the preparedness of the Canadian hospital system to accommodate expected surges in patient demand and evaluating intervention strategies to mitigate impact. The sixth is a policy-oriented paper discussing pandemic policy options within the context of public health ethics and risk management principles. Pandemic vaccination, antiviral treatment, voluntary isolation and personal protective measures were identified as the most cost-effective interventions available. Antiviral prophylaxis, community-contact reduction, school closure and quarantine were less effective, and tended to be associated with higher associated economic burdens. The timely implementation of layered intervention strategies appears likely to protect hospital-resource adequacy, though areas of Southwestern Ontario appear to be more vulnerable to surges in patient demand. However, the potential for high health and economic burdens, coupled with the uncertain severity of future pandemics, necessitates a flexibility in preparedness and response plans.