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

Ashleigh Tuite; David N Fisman; Amy L Greer

This pathogen represents a significant challenge for public health, pandemic planning, and healthcare systems. The SARS-CoV-2 virus is highly transmissible (4) (5) (6) (7) . It causes moderate to severe clinical outcomes in approximately 20% of all recognized infected individuals (5, 8, 9) . In the absence of a vaccine, public health responses have focused on the use of non-pharmaceutical interventions (NPIs) (10) . These NPIs include: (1) "case-based" measures such as testing, contact tracing, isolation, and quarantine, and (2) "non-case-based" measures such as reducing the probability of transmission given an effective contact (e.g. hand hygiene, and cough etiquette), and social distancing measures to reduce the contact rate in the population. Social distancing minimizes opportunities for person-to-person transmission of the virus to occur. These social distancing measures include some combination of school closure, teleworking, cancellation of group activities and events, and a general overall reduction in community contacts. While they are expected to be effective in reducing transmission of SARS-CoV-2, they are also associated with substantial economic costs and social disruption.