Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Infect Dis. May 15, 2020; 10(1): 1-13
Published online May 15, 2020. doi: 10.5495/wjcid.v10.i1.1
COVID-19 compared to other epidemic coronavirus diseases and the flu
James A Ayukekbong, Michel L Ntemgwa, Solange A Ayukekbong, Eta E Ashu, Terence A Agbor
James A Ayukekbong, Solange A Ayukekbong, Eta E Ashu, EpiTech Public Health, Nanaimo, BC V9R 0H7, Canada
Michel L Ntemgwa, Natural and Non-prescription Health Products Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON K1A 0K9, Canada
Eta E Ashu, Cancer Care Ontario, Toronto, ON M5P 3L6, Canada
Terence A Agbor, DynaLIFE Medical Labs, Edmonton, AB T5J 5E2, Canada
Terence A Agbor, Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, AB T6G 2R3, Canada
Author contributions: Ayukekbong JA did the initial literature search, wrote the first draft as well as coordinated the writing of the entire manuscript; Ayukekbong S designed the outline, performed literature search and contributed in writing; Ashu EE, Ntemgwa ML and Agbor TA reviewed the first draft, provided relevant editing as well as writing and performed reference formatting.
Conflict-of-interest statement: The authors declare that they have no competing interests.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: James A Ayukekbong, Doctor, EpiTech Public Health, Nanaimo, BC V9R 0H7, Canada.
Received: March 17, 2020
Peer-review started: March 17, 2020
First decision: April 3, 2020
Revised: April 15, 2020
Accepted: April 24, 2020
Article in press: April 24, 2020
Published online: May 15, 2020

Coronaviruses are among the largest group of known positive - sense RNA viruses with a wide range of animal hosts as reservoir. In the last two decades, newly evolved coronaviruses such as the severe acute respiratory syndrome coronavirus (SARS-CoV) which caused the infamous 2002 outbreak, the Middle East respiratory syndrome coronavirus (MERS-CoV) which caused an outbreak in 2012, and now the SARS-CoV-2 [responsible for the current coronavirus disease 2019 (COVID-19)] have all posed notable threats to global public health. But, how does the current COVID-19 outbreak compare with previous coronaviruses diseases? In this review, we look at the key differences between SARS-CoV, MERS-CoV, and SARS-CoV-2, and examine challenges in determining accurate estimates of the severity of COVID-19. We discuss coronavirus outbreaks in light of key outbreak severity indicators including, disease fatality, pathogen novelty, ease of transmission, geographical range, and outbreak preparedness. Finally, we review clinical trials of emerging treatment modalities and provide recommendations on the control of COVID-19 based on the mode of transmission of the coronaviruses. We also recommend the development and use of a standardized predictive epidemic severity models to inform future epidemic response.

Keywords: Severe acute respiratory syndrome, SARS, Middle East respiratory syndrome, MERS, COVID-19, SARS-CoV2, Coronaviruses, Influenza, Flu, Respiratory viruses

Core tip: In this review, we look at differences and similarities between severe acute respiratory syndrome coronavirus, Middle East respiratory syndrome coronavirus, and severe acute respiratory syndrome coronavirus 2 and we discuss the challenges in the determination of case fatality rates in pandemics like the current and propose the need for standardization of predictive epidemic severity models that considers critical factors that can influence the severity of outbreaks.