Each year, hundreds of cases of dengue are imported into Canada via travellers from endemic countries. However, this is subject to underreporting and misclassification due to lack of awareness of this domestically uncommon disease.

The threat of autochthonous mosquito-borne disease transmission in Canada is growing. Aedes albopictus, a vector for dengue virus, has become established in southern Ontario. As the Canadian landscape for vectors and vector-borne pathogens evolves due to climate change, it is imperative to understand the potential for local transmission initiated by imported cases.

A compartmental SEIR-SEI model was developed to explore dengue transmission in Windsor, Ontario. The model introduces dengue cases into the population to explore the possibility of an autochthonous outbreak during a limited period of the year. The model accounts for temperature and precipitation drivers of mosquito development and was calibrated on mosquito population data from Windsor.

As no locally acquired human cases of dengue have ever occurred in Canada, outbreak data from the Pesaro and Urbino province in Italy with similar meteorological conditions to Windsor was used to model a potential outbreak in Canada.

Our results indicate the importance of timing of introduction events. The model shows the highest outbreaks occurring when cases are introduced in July and August with a median outbreak size of 62 cases per 100,000 people in 1000 simulations. The findings highlight the growing local risk of mosquito-borne diseases in Canada and the importance of increasing awareness of exotic pathogens.

Keywords: Aedes albopictus, compartmental model, forecasting, mosquito, One Health