Severe acute respiratory syndrome coronavirus 2

Pathogen category: (+)ssRNA viruses

Also known as

• SARS-CoV-2
• 2019 novel coronavirus (2019-nCoV)

 

Disclaimer:

At the timing of writing, COVID-19 has been a known clinical entity for just over one year. 

This is an area of intense active research. 

The information presented herein is likely to change many times as new evidence is gathered and reported.

 

Pathology

• Coronavirus Disease 2019 (COVID-19)
• Pathophysiology

 

Characteristics

• SARS-CoV2 has been described by virologists as unusually proficient at suppressing the immune response until the infection is very advanced. There can be almost no signs of viral infection in tissues which are heavily burdened with compromised cells. As a result, asymptomatic carriers can spread the virus for days before they develop any signs or symptoms.
• SARS-CoV2 can survive on hard surfaces for up to 72 hours.
• Hard surfaces can be effectively cleaned with alcohol or soap solutions.
  

 

Features

Genome

• The genome is contained within a single, linear, positive-sense RNA strand.
  
• Size (# base pairs): 29,903.
  

Structural proteins

• Nucleocaspid protein (N): Houses the viral genetic material.
• Envelope (E): Forms the outermost viral envelope.
• Membrane (M): Forms the outermost viral envelope.
• Spike (S): Forms the outermost viral envelope. Binds to host cell. See 'Exploits' below.
  

Viral envelope 

• The virus is surrounded by a protective lipid (fatty) bilayer.
  

Virulence factors

• At least 3 identified. With futher research, more factors may be recognised. 
• Promote viral shedding.
• Inhibit host immune response.
• Supression of interferon signalling. 

Exploits

• ACE2 (Angiotensin Converting Enzyme 2). A cell surface enzyme. The viral spike protein has evolved a Receptor Binding Domain, with high binding affinity for ACE2.
  
• TMPRSS2 (Transmembrane protease, serine 2): A transmembrane enzyme. SARS-CoV1 and SARS-CoV2 have evolved to initiate cell entry when they interact with this enzyme on the cell surface.
  

History

 

Taxonomy

• Category: Virus     
• Realm: Riboviria
• Kingdom: Orthornavirae
• Phylum: Pisuviricota
• Class: Pisoniviricetes
• Order: Nidovirales
• Family: Coronaviridae
• Genus: Betacoronavirus
• Subgenus: Sarbecovirus
• Species: Severe acute respiratory syndrome–related coronavirus
• Strain: Severe acute respiratory syndrome coronavirus 2
  

 

See also

• SARS-CoV-2 VUI-202012/01 (A later strain. Significantly more transmissible.)
• Severe acute respiratory syndrome-related coronavirus (An earlier strain). 
• SARS-CoV-2 Cluster 5 (First detected in Denmark)
• SARS-CoV-2 501.V2 Variant (First detected in South Africa)