Is The Coronavirus Disease (COVID-19) The Same As SARS?

Wednesday, June 3, 2020, 22:51

The coronavirus disease (COVID-19)is an infectious disease caused by coronaviruses, a family of viruses that also causes severe acute respiratory syndrome (SARS). Both COVID-19 and SARS are caused by a strain of coronaviruses that caused SARS, known as SARS-CoV in 2003 and currently causing coronavirus disease, known as SARS-CoV-2.

On 11 February 2020, the International Committee on Taxonomy of Viruses (ICTV) named the novel coronavirus - SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). This name was given because the virus is genetically related to the coronavirus responsible for the SARS outbreak in 2003.

In this article, we will explain the similarities and differences between COVID-19 and SARS.

What Is A Coronavirus?

Coronaviruses are a family of viruses that have spike-like projections on their surface that look like crowns. Corona means 'crown' in Latin and that's how this virus got its name.
COVID-19 is the third known zoonotic coronavirus disease after severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) [1].

A new type of coronavirus can appear when an animal coronavirus develops the ability to transmit a disease to humans and this is called zoonotic transmission.

A study showed that SARS-CoV-2 was a chimeric virus between a bat coronavirus and a coronavirus of unknown origin. The researchers found that the chain of transmission started from bats to humans [1].

Symptoms Of Coronavirus Disease

The symptoms are fever, cough, difficulty in breathing, fatigue, runny nose, headache, body pain, sore throat, diarrhoea and nausea.

Transmission Of Coronavirus Disease

People can contract COVID-19from another infected person who has the virus. The disease spreads easily from person to person through small water droplets from the nose or mouth when an infected person coughs or sneezes.

The viral load appears to be the highest in the throat and nose of people with COVID-19 [2].

What Is Severe Acute Respiratory Syndrome (SARS)?

Severe acute respiratory syndrome (SARS) is a coronavirus that caused the SARS outbreak in 2002-2003. The SARS virus passed from bats to an intermediate animal host, the civet cat, before passing on to humans [3].

Symptoms Of SARS

SARS causes symptoms like shortness of breath, fever, cough, malaise, body pain, headache, chills and diarrhoea.

Transmission Of SARS

The transmission of SARS occurs primarily from person to person contact. SARS-CoV spreads through respiratory droplets when an infected person coughs or sneezes.

Molecular Factors Of COVID-19 And SARS-CoV

A study found the complete genetic information (genome) of SARS-CoV-2 which showed that it was closely related to two bat-derived SARS-like coronaviruses, bat-SL-CoVZC45 and bat-SL-CoVZXC21, but was more distant from SARS-CoV (about 79 per cent) and MERS-CoV (about 50 per cent) [4].

Receptor Binding Of COVID-19 And SARS-CoV

The receptor binding site was also compared with SARS-CoV-2 and SARS-CoV. When a virus enters a cell of the human body, it needs to interact with proteins on the cell's surface (receptors) and the virus does this through proteins on its own surface.

Coronavirus enters the host cells mediated by the transmembrane spike (S) glycoprotein that forms homotrimers coming out from the viral surface. This glycoprotein is responsible for binding to the host cell receptor.

A study showed that both SARS-CoV-2 and SARS-CoV bind to the host cell receptor with same tightness and the intensity is much higher in SARS-CoV-2. This is the reason why SARS-CoV-2 is appearing to spread more easily than the SARS-CoV [5].

To Conclude...

COVID-19 and SARS are both caused by coronaviruses that originated in bats before they were transmitted to humans by an intermediate host. There are some differences and similarities between COVID-19 and SARS.