Tracking the Covid-19 pandemic : Simple visualization of the epidemic states and trajectories of select European countries & assessing the effects of delays in official response.

Antoine Kevorkian; Thierry Grenet; Hubert Gallee

As data span several orders of magnitude, logarithmic scales are used. It is clearly visible that within individual variations and data collection rule modifications, the China trajectory is tracked rather closely by the other countries. Figure 1 : Number of new daily confirmed cases as a function of N, which is the total number of confirmed cases since onset of Covid-19 epidemic for China, Italy, France, Germany and Spain. Each point corresponds to a specific day. All of the countries exhibit similar epidemic progression within a certain band. Projection for Italy (dotted line and blue points) takes into account a 13-day delay beyond lockdown to reach the maximum daily confirmed cases as observed in China. The sharp peak on China's curve is due to a change of counting method on Fed 12 and is discussed in Appendix 1.