Question

How does COVID-19 compare with SARS and MERS?

Answer 1

Coronaviruses are a large family of enveloped RNA viruses that mostly infect birds and mammals.

But in humans, they can cause mild infection in the upper respiratory tract, like the common cold, but also more serious lower respiratory tract infections.

These infections can manifest as bronchitis, pneumonia, or a severe respiratory illness, such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), or coronavirus disease 19 (COVID-19).

Each of the three new coronaviruses that has emerged since the turn of the century has caused respiratory disease outbreaks, but each has also displayed unique features.

SARS and MERS have significantly higher case fatality rates than COVID-19. Yet COVID-19 is more infectious — the underlying SARS-CoV-2 virus spreads more easily among people, leading to greater case numbers. Despite the lower case fatality rate, the overall number of deaths from COVID-19 far outweighs that from SARS or MERS.

There have been no cases of SARS for over a decade. But MERS is an ongoing public health concern. In the past, coronaviruses that cause the common cold in humans also emerged, possibly in the same way as did the current pandemic.