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

“Novel” Coronaviruses

• Novel coronaviruses predominantly in LOWER respiratory tract
• SARS, MERS, SARS-CoV-2
• Don’t forget other LRIs:
• Viral Pneumonia: Influenza (A/B), Adenovirus, Parainfluenza (Type 1-4), Respiratory syncytial virus, Human metapneumovirus, NL63
• Typical bacteria CAP: Lobar – Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis; Gram neg, anaerobic if aspiration
• Bacterial bronchitis or atypical CAP: Bordetella pertussis, Mycoplasma pneumoniae, and Chlamydia pneumoniae
• SARS (2002-2003): Contained. CFR 10%. >50% mortality in >60 years.
• MERS: Not Contained. CFR 35%. Linked to direct camel exposure.
• High healthcare worker infection and other nosocomial spread
• Aerosolization during procedures (intubation, nebs, BiPAP, suctioning)

Novel CoV attachment

• ACE-2 Receptors
• Type 2 alveolar cells - highest
• Bronchial epithelia
• Tongue > buccal epithelia
• Upper Intestinal epithelia
• Myocardial cells
• Kidney proximal tubule cells
• Bladder urothelial cells
• SARS-CoV-2 binds to ACE-2 Receptor 10-20x more strongly than SARS-CoV
• Question of ADEs (Antibody Dependent Enhancement)
• Antibodies can create a backdoor enhancement for viral replication
• Implications on viral replication and vaccine development safety

https://www.nature.com/articles/s41368-020-0074-x

https://jvi.asm.org/content/94/5/e02015-19

SARS-Cov-2 origin

• Bat to a mammal (pangolin?) to human in Nov/Dec 2019
• Pangolins used in Chinese medicine
• Probable link to seafood/exotic animal market
• Other plausible theory:
• Wuhan Level 4 Biohazard lab experimental

animals sold for human consumption