Covid-19 sars-coV-2 Lisa Gilbert, md, faafp, ctropMed 3/17/20 covid-19 sars-coV-2 2019-nCov hcoV-19

COVID-19 SARS-CoV-2 Lisa Gilbert, MD, FAAFP, CTropMed 3/17/20

COVID-19 SARS-CoV-2 2019-nCov HCoV-19

Disease
Virus Name

7 Human Coronaviruses: 4 normal; 3 “novel”

Alpha: HCoV-229E, HCoV-NL63 Beta: HCoV-HKU1, HCoV-OC43, MERS-CoV, SARS-CoV, SARS-CoV-2

Coronavirus Structure

• Medium-sized virus size, but largest mRNA genome
• Enveloped +ve stranded RNA
• mRNA encased in nucleocapsid
• Lipid Bilayer – Soap works to disrupt this!

Corona = Crowns for Spikes

• Glycoprotein Spike (S) Peptomer
• Spikes allow it to attach to human cell receptors in upper or lower airway

Coronavirus Genome

• Encodes four or five structural proteins:
• S – spikes on the outside; mediates receptor binding
• M – membrane protein; assists viral assembly
• N – nucleocapsid protein; regulation of viral RNA synthesis, may interact with M protein during virus budding 
• E – small envelope protein; function necessary but not fully understood
• HE – hemagglutinin-esterase glycoprotein in Beta coronavirus OC43 and HKU1 only; enhances uptake into mucosal cells

Video and article on how coronavirus replication in cells occurs: https://www.youtube.com/watch?v=Eeh054-Hx1U

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4369385/

Upper Respiratory Infections

• Normal human coronaviruses cause 5-10% of common cold/URIs, with outbreaks to 30% of common cold
• 229E and NL63 (alpha coronaviruses)
• OC43 and HKU1 (beta coronaviruses)
• These four predominately attach to receptors in UPPER airway (receptors: aminopeptidase N, dipeptidyl peptidase 4)
• Seasonality unpredictable (generally winter, but persists year round), different pattern in tropics than temperate regions
• URI symptoms, croupy or dry cough, rarely pneumonia (except sometimes NL63, but usually just causes croup); Mild diarrhea in infants
• Don’t forget other URI viruses: Rhinovirus, Influenza A/B, Adenovirus, Parainfluenza, Respiratory syncytial virus, Human metapneumovirus