We have applied our previously published, Incidence Decay and Exponential Adjustment (IDEA) model to better understand the 2014 PEDV outbreak in Ontario. Using our simple, 2-parameter IDEA model, we have evaluated the early epidemic dynamics of PEDV on Ontario swine farms. We estimated the best-fit R0 and control parameter (d) for the farm-to-farm transmission component of the outbreak by fitting the model to publically available cumulative incidence data. 

Funding: Natural Sciences and Engineering Research Council (NSERC)

Key collaborators: Kelsey Spence (PhD candidate), and Dr. Emma Gardner (PhD candidate).


We have developed an improved understanding of the ecology and demography of semi-urban domestic dog population, as well as dog ownership practices in Villa de Tezontepec, Hidalgo, Mexico. In semi-urban areas of Mexico, free-roaming dogs present a public health risk to humans. These findings are an essential first step for the design of effective dog population control and rabies vaccination programs.

Funding: Canada Research Chairs program and MITACS Globalink      

Key collaborators: Luz Maria Kisiel (MSc thesis student), Dr. Andria Jones-Bitton (University of Guelph) and Health Services of the State of Hidalgo, Mexico. 

Pandemic Planning

Our group was heavily involved in the public health response during the 2009 influenza A/H1N1 pandemic in Canada. We were a part of the first group to describe the epidemiological parameters during the pandemic using data from the beginning of the outbreak in Ontario, Canada. This work represented an important early collaboration between academics and provincial public health officials during a public health crisis. The research findings helped to guide provincial and federal decision-making regarding optimal public health intervention strategies throughout the pandemic period in Canada. This paper is a seminal paper from the 2009 pandemic and as a result has been widely cited by other authors since it was published.   

We have also completed modeling work in collaboration with various Canadian Pandemic Influenza Plan (CPIP) Task Groups coordinated by the Public Health Agency of Canada.  This is the first time that mathematical modellers have played a major role in developing models in direct collaboration with a federal working group for the express purpose of using models to help guide discussion and decision-making.

Vaccine Preventable Diseases


We have developed mathematical models to determine the impact of vaccination strategies for  vaccine-preventable diseases including pandemic influenza and pertussis. These models have allowed us to examine a variety of “what-if” scenarios regarding alternative vaccination strategies, uptake in different age groups and different vaccine efficacy to suggest how best to optimize a vaccine intervention in order to minimize overall morbidity and mortality and/or disease transmission in the population. This work has contributed to Canadian recommendations regarding the provision of pertussis booster vaccination to healthcare workers. Additional work on pandemic influenza vaccine strategies was a significant factor in the development of the Canadian pandemic vaccine prioritization list in 2009 and was recognized internationally in 2010 when Ashleigh Tuite and Amy Greer were awarded the Senior Lupina Prize for Dynamic Modelling in Health Policy.

Vulnerable Populations

The burden of infectious diseases in Canada is distributed in a geographically heterogeneous fashion with northern populations having higher burdens for a variety of well-documented reasons. We have demonstrated that pandemic influenza was in fact, far more transmissible in Nunavut communities than other areas. We used empirical data to demonstrate that the differential severity of the pandemic in these regions can be explained partly by differential transmissibility. This finding suggested the need for more nuanced, targeted or population-specific control strategies to be considered when a public health crisis affects our vulnerable northern populations. This work was completed with the support of the Nunavut Department of Health.  We maintain ongoing collaborations with both Nunavut and the Yukon Territory to provide modeling expertise for applied public health problems. We have worked with the Yukon Territory to examine the potential health impacts of increasing Chlamydia screening in men within the Territory. 

Modeling for Non-Technical Audiences & Knowledge Translation


During the first wave of the 2009 pandemic, there was much discussion about using mathematical models to better understand optimal intervention strategies for pandemic influenza. Many public health professionals and clinicians were not familiar with modeling and we organized a significant number of knowledge translation activities for non-technical audiences to provide an introduction to the topic. In addition, we have contributed extensively to the training of non-technical staff at the Public Health Agency of Canada so that individuals in policy related positions can more effectively communicate and collaborate with mathematical modelers both within the Agency and within academia to address important public health problems.