Estimating cases of COVID-19 from Daily Death Data in Italy

Raheem, Ali

COVID-19 is an emerging infectious disease which has been declared a pan- demic by the World Health Organisation. Due to limited testing capacity for this new virus, variable symptomatology the majority of infected showing non-specific mild or no symptoms it is likely current prevalence data is an underestimate. Methods: We present an estimate of the number of cases of COVID-19 com- pared to the number of confirmed case in Italy based on the daily reported deaths and information about the incubation period, time from symptom on- set to death and reported case fatality rate. Results: Our model predicts that on the 31st of January 2020 when the first 3 infected cases had been identified by Italian authorise there were already nearly 30 cases in Italy, and by the 24th of February 2020 only 0.5% cases had been detected and confirmed by Italian authorities. While official statistics had 132 confirmed case we believe a more accurate estimate would be closer to 26000. With a case-doubling period of about 2.5 days.