Comparative analysis of transmissibility and case fatality ratio of SARS, MERS and COVID-19 via a mathematical modeling approach

Coronavirus epidemics emerged in the 1960s and the world has witnessed seven coronavirus outbreaks since then. Four of the coronaviruses instigate human influenza while the rest: Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) and Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) trigger severe respiratory disorders (SARS, MERS and COVID-19 respectively). The etiology of SARS, MERS and COVID-19 are similar but their epidemiology, in terms of incubation period, infectivity, case fatality ratio and the serial interval differ. In an attempt to compare the infectivity and case fatality ratio of the diseases, a mathematical model was considered for each disease. The key epidemiological quantity, the basic reproduction number, was derived for each model to examine the transmission potential of each disease. The mortality rates for the diseases were also investigated by considering the global report of COVID-19 as of October 1 2020 together with the history of SARS and MERS. Results from the computations showed that COVID-19 had the highest transmission potential and at the same time the lowest case fatality ratio. It was also revealed that COVID-19 would have wrecked more havocs had its case fatality ratio was as high as that of MERS.