Estimating Spot Prevalence of COVID-19 from Daily Death Data in Italy

Ali Raheem

This model used the spot daily reported deaths which may lag the true date of death due to delays in confirming and then reporting causes of death if COVID-19 was not diagnoses ante mortem. Our estimate of point prevalence varies proportionally to the error in deaths. Deaths due to infection not reported will cause an underestimate in prevalence. Estimating true mortality rates is difficult, and our estimate varies with the reciprocal of the error in the mortality rate. Underestimating mortality will lead to increase in predicted cases. As shown in Figure 3 due to this our model is relatively robust for an error in case fatality ratio 4-10%, which is comparable to reported case fatality ratio estimates. This is an evolving pandemic and due to the long incubation and time to death periods only a short period of point prevalence's can be estimated. Especially during the incubation period it's possible for those infected with SARS-CoV2 to travel into Italy, meaning cases predicted may not have acquired the infection in Italy. 5 All rights reserved. No reuse allowed without permission. author/funder, who has granted medRxiv a license to display the preprint in perpetuity. author/funder, who has granted medRxiv a license to display the preprint in perpetuity.