Estimation of the Case Fatality Ratio of Middle East Respiratory Syndrome based on Patients' Comorbidities with Application to the MERS-CoV Epidemics in the Republic of Korea, 2015

In an early stage of the course of the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) outbreak in Korea in 2015, the Centers for Disease Control and Prevention of Korea and several studies reported estimated Case Fatality Ratios (CFRs) that were significantly different. Here, we propose an estimation method based on the commonly quoted naive estimator of CFR utilizing the number of in-hospital patients with comorbidities, as well as the numbers of cumulative confirmed and dead patients up to a certain date. We compared the proposed estimator with two naive and an integral method estimator by simulation experiments under the individual based susceptible-exposed-infected-recovered model and analysis of data from the 2015 epidemic of MERS-CoV in Korea. The proposed estimator better simulated and analyzed the Korean MERS data.