Title: COVID-19, SARS and MERS: are they closely related?
Authors: Nicola Petrosillo, Giulio Viceconte, Onder Ergonul, Giuseppe Ippolito, Eskild Petersen
Background: The 2019 novel coronavirus (SARS-CoV-2) is a new human coronavirus which is spreading with epidemic features in China and other Asian countries with cases reported worldwide. This novel Coronavirus Disease (COVID-19) is associated with a respiratory illness that may cause severe pneumonia and acute respiratory distress syndrome (ARDS). Although related to the Severe Acute Respiratory Syndrome (SARS) and the Middle East Respiratory Syndrome (MERS), COVID-19 shows some peculiar pathogenetic, epidemiological and clinical features which have not been completely understood to date.
Objectives: We provide a review of the differences in terms of pathogenesis, epidemiology and clinical features between COVID-19, SARS and MERS.
Sources: The most recent literature in English language regarding COVID-19 has been reviewed and extracted data have been compared with the current scientific evidence about SARS and MERS epidemics.
Content: COVID-19 seems not to be very different from SARS regarding its clinical features. However, it has a fatality rate of 2.3%, lower than SARS (9.5%) and much lower than MERS (34.4%). It cannot be excluded that because of the COVID-19 less severe clinical picture it can spread in the community more easily than MERS and SARS. The actual basic reproductive number (R0) of COVID-19 (2-2.5) is still controversial. It is probably slightly higher than the R0 of SARS (1.7-1.9) and higher than MERS (<1),. The gastrointestinal route of transmission of SARS-CoV-2, which has been also assumed for SARS-CoV and MERS-CoV, cannot be ruled out and needs to be further investigated.
Implications: There is still much more to know about COVID-19, especially as concerns mortality and capacity of spreading on a pandemic level. Nonetheless, all of the lessons we learned in the past from SARS and MERS epidemics are the best cultural weapons to face this new global threat.
This timespace follows the World Health Organization's situation reports regarding the COVID-19 outbreak that started in Hubei, China, in January 2020. Cover photograph taken in Japan by Jérémy Stenuit.