Mathematical modeling of COVID-19 transmission and mitigation strategies in the population of Ontario, Canada

Ashleigh Tuite; David N Fisman; Amy L Greer

Testing was assumed to move individuals with non-severe symptoms from the infectious to isolated compartments. Isolated cases were assumed to have reduced transmission compared to non-isolated cases. Social distancing measures were assumed to reduce the number of contacts per day across the entire population. Details of parameters that were varied under different interventions are included in Table 2 . For the base case, we assumed that there was a degree of testing and isolation occurring and that a proportion of exposed cases were quarantined. We then added in additional control measures: (i) enhanced testing and contact tracing; (ii) restrictive social distancing measures; and (iii) a combination of enhanced testing and contract tracing, along with less restrictive social distancing than in (ii). We considered two approaches to implementing interventions: (i) fixed durations and (ii) a dynamic approach with interventions turned on and off based on the number of cases requiring ICU care in the population. We focused on ICU capacity, since this is expected to be most limited resource during the COVID-19 epidemic. Prior to emergence of COVID-19, Ontario had approximately 1300 ICU beds with associated ventilators; but 90% were occupied by individuals with non-. CC-BY-NC 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity.