Minisymposium lectures

Role of case introductions in the community spread of infectious diseases

Julien Arino

true  Tuesday, 10:00 ! Ongoingin  Schultz Theatrefor  30min

During the COVID-19 pandemic, local and national governments often took the decision to suspend or severely limit travel of individuals originating in regions where new variants of SARS-CoV-2 were observed to be spreading. However, the efficacy of these measures was debatable and while there were success stories, there were also many instances where the gain was hard to gauge. In this presentation, I will discuss models with a so-called importation layer that allow to evaluate the contribution of introductions in the overall spread taking place in a given location. I will show that, unsurprisingly, while introductions are crucial in seeding the local propagation, they are quickly surpassed by community-generated cases. This indicates that the timing of travel restriction measures is extremely important, a fact that was mostly overlooked in the decision process.

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