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

A precise estimation of the final death toll that can be expected is outside the scope of this note. Calculating this would require knowledge of the actual mortality rate; e.g. the final number of deaths relative to the final number of infections. If symptomatic cases are the only ones counted, then the number of infection cases are underestimated, and the apparent mortality rate is computed to be higher than it actually is. During the epidemic progression this apparent mortality rate may change over time. Since the epidemic onset in Italy for instance, as of March 15 a steady increase in the apparent mortality rate can be observed. This may be due to a combination of causes: a decrease in the efficiency of case detection as the number of infections grows, a concomitant decrease in medical care efficiency, and effects linked to the time-lag between the detection of early symptoms and actual death [5] . If one uses the WHO's average mortality rate estimate of 3.4% then Italy's final death toll would rise to approximately 5,000. However with the significantly higher apparent mortality rate of 8.3% observed on March 18, 2020 [2] and its still increasing trend, more than 10.000 deaths may be expected. This range of numbers should be compared to the approximately 3,300 deaths in China.