Why daily death tolls have become unusually important in understanding the coronavirus pandemic

Significantly Improved COVID-19 Outcomes in Countries with Higher BCG Vaccination Coverage: A Multivariable Analysis

“…Despite the intense effort, the knowledge on the COVID-19 SARS-CoV-2 virus is fragmented and key epidemiological parameters are still missing (4)(5)(6)(7)(8)(9). With over 250k reported deaths and an average number of 33 deaths per million (DPM, as of May 5th, 2020), the death toll remains a reliable measure for monitoring the spread and progression of the disease across countries (10). While for some European countries such as Belgium, Spain, Italy, and the UK the DPM is >400, other infected countries (e.g., Brazil, Turkey, Israel, Hungary) are closer to the world average.…”

Tracking the onset date of the community spread of SARS-CoV-2 in western countries

“…The reported number of deaths provides a more reliable tracker of the SARS-CoV-2 epidemic's progress within a country than counts of diagnosed cases because there are less affected by substantial underreporting. (27) Furthermore, the cumulative number of reported deaths represents a timedelayed tracker of the SARS-CoV-2 epidemic (median time between infection and death of around three weeks) and thus provides valuable information on early epidemic dynamics even when data is obtained after implementation of control measures to reduce the viral spread. (28,29) To infer the probable onset date of the community spread of SARS-CoV-2 in a given location, we assumed that: (a) as soon as the virus starts spreading locally, the epidemic starts to grow exponentially and the cumulative number of deaths starts to increase exponentially 20 days later; (b) the rate of exponential growth of the number of deaths remains roughly constant during the epidemic early weeks; and (c) the infection fatality ratio of SARS-CoV-2 is around 1%.…”

Measures of mortality in COVID-19: beyond the death toll

“…The cumulative death graphs also indicate the current and past trends and whether they are about to get flattened in relation to deaths. In Figure 1, it is clearly visible that daily deaths are still rising in the USA while in other countries, there is a decline or flattening trend as of 8 April 2020 (8).…”

“…The total number of deaths in a day has emerged as a useful statistic for tracking the progress of COVID-19 in different regions. The rate at which the daily death counts increase or decrease is an indicator of what the virus is doing in a population (8). The trends in the cumulative deaths in a country give a clear indication as to whether the epidemic is under control or whether more stringent measures need to be adopted.…”

“…Due to lack of testing in many countries and the virus's ability to spread in people who do not show symptoms, counting the number of infections has been very difficult. Therefore, since COVID-19 has also been more fatal than many other recent epidemics, understanding the pandemic mainly through its mortality parameters has been useful (8).…”