Tracing DAY-ZERO and Forecasting the Fade out of the COVID-19 Outbreak in Lombardy, Italy: A Compartmental Modelling and Numerical Optimization Approach.

Lucia Russo; Cleo Anastassopoulou; Athanassios Tsakris; Gennaro Nicola Bifulco; Emilio Fortunato Campana; Gerardo Toraldo; Constantinos Siettos

is the (which was not peer-reviewed) The copyright holder for this preprint . https://doi.org/10.1101/2020.03.17.20037689 doi: medRxiv preprint critical knowledge in our arsenal to combat the pandemic. The tracing of DAY-380 ZERO, in particular, is of outmost importance. It is well known that minor perturbations in the initial conditions of a complex system, such as the ones of an outbreak, may result in major changes in the observed dynamics. No doubt, a high level of uncertainty for DAY-ZERO, as well as the uncertainty in the actual numbers of exposed people in the total population, raise several barriers 385 to our ability to correctly assess the state and dynamics of the outbreak, and to forecast its evolution and its end. Such pieces of information would lower the barriers and help public health authorities respond fast and efficiently to the emergency.