4. • China appears to have looked other way, is liable for exporting the
virus, appears complicity of even WHO
• HCoV-OC43, HCoV-HKU1, HCoV-NL63, and HCoV-229E
SARS 2002 MERS COVID 19
INFECTIONS 8098 2494 453074
DEATH 774 858 20519
CFR 10% 37%
S GLYCOPROTEIN
S1-Receptor
binding
S2 – Cell
membrane fusion
Furin Cleavage site
YES
NO
YES
NO
YES
YES
RECEPTOR hACE2 DPP4 hACE2
Reservoir Bats Bats Bats
Intermediary host palm civets
racoon dogs
dromedary camels Unknown
Potential vaccine
5. SARS-CoV-2 uses ACE2 to enter target cells
SARS-CoV-2 and SARS-CoV bind with similar
affinities to ACE2
Structures of SARS-CoV-2 spike glycoprotein in
two conformations
SARS-CoV polyclonal antibodies inhibit SARS-
CoV-2 spike-mediated entry into cells
6. COVID -19 – Zoonotic
• SARS CoV 2 (79% sequence identity with SARS-CoV – SARS-2002)
• Family coronaviridae Genus beta coronavirus Subgenus sarbecovirus
• Natural Host & Reservoir – Horse Shoe bats, Intermediate host --?? Snakes,
yet to discover
• ACE-2 - receptor for cell entry
(Converts Angiotensin II
(Vasoconstrictor) Angiotensin 1-7
(Vasodilator)
• Wet market (Huanan Seafood Wholesale
Market in Wuhan City, South china)
• Live animals
7.
8.
9. • R0 value - 2.2 (1.4-3.8) - similar to SARS-CoV-1 and pandemic
influenza
23. Prevention (“Flattening the Curve”)
• Median daily reproduction number (Rt) in Wuhan declined from 2.35 1 week before travel
restrictions were introduced on January 23, 2020, to 1.05 1 week after.
• Utilizing a stochastic transmission model parameterized to the COVID-19 outbreak, Hellewell et al
concluded that “highly effective contact tracing and case isolation is enough to control a new
outbreak of COVID-19 within 3 months.
• A study published on March 16, 2020 by the Imperial College of London and WHO compared 2
fundamental policy strategies to reduce the rate of spread of SARS-CoV-2: “(a) mitigation, which
focuses on slowing but not necessarily stopping epidemic spread – reducing peak healthcare
demand while protecting those most at risk of severe disease from infection, and (b) suppression,
which aims to reverse epidemic growth, reducing case numbers to low levels and maintaining that
situation indefinitely.” The study found that “…optimal mitigation policies (combining home
isolation of suspect cases, home quarantine of those living in the same household as suspect
cases, and social distancing of the elderly and others at most risk of severe disease) might reduce
peak healthcare demand by two-thirds, and deaths by half. However, the resulting mitigated
epidemic would still result in hundreds of thousands of deaths and health systems (most notably
intensive care units) being overwhelmed.” This explains and lends support to the aggressive
measures taken by countries in recent days to battle the spread of the SARS-CoV-2 pandemic.
24. • Reports from Italy suggest that up to 20% of healthcare professionals
dealing with COVID-19 patients became infected with the virus, with some
reported deaths.
• assign one person to monitor compliance to PPE in the ED at all times
• half-lives for SARS-CoV-2 virus on various surfaces as follows:
• 1.1 hours in aerosols
• 0.77 hours on copper
• 3.46 hours on cardboard
• 5.46 hours on steel
• 6.81 hours on plastic.
• virus can remain viable and infectious in aerosols for hours and on surfaces
up to days
25. • SARS-CoV-2 virus being found in the feces of seropositive patients,
likelihood of fecal-oral and, hence, hand transmission is very high
• Healthcare professionals and patients should follow standard hand-
washing techniques
• wash hands with soap and water for at least 20 seconds, especially after going
to the bathroom; before and after eating; and after blowing the nose,
coughing, or sneezing
• If soap and water are not available, one should use an alcohol-based sanitizer
with at least 60% alcohol.
26. • Additional guidelines for those with close contacts and suspicious
exposures include “strong recommendations” for
• an observation period of 14 days, wearing of a facemask if coughing or with
URI symptoms
• prioritizing private transportation over public
• prenotification of the hospital (or clinic) prior to patient arrival
• cleansing of the transport vehicle with 500 mg/L chlorine-containing
disinfectant, with open ventilation.
27. Use of Personal Protective Equipment
Doffing of personal protective equipment (PPE) is often the highest-risk procedure during the patient-
physician interaction, in terms of spread of SARS-CoV-2.
28.
29. emergency clinicians should re-emphasize to the
lay public what we already know of viral
respiratory infections
• that seeking treatment in a hospital setting for mild symptoms, fever,
mild diarrhea, or cough alone likely carries with it more risk than
benefit, both to themselves and to vulnerable patients around them.
• Patients experiencing severe symptoms such as difficulty breathing,
high fever (>39°C), and an inability to tolerate oral hydration should
seek emergency evaluation
33. Treatment Strategies
• Recent in vitro studies conducted on COVID-19 have found that
REMDESIVIR and CHLOROQUINE inhibit viral infection of cells with low
micromolar concentration with a high selectivity index.
• The National Taskforce for COVID-19 recommends the use of hydroxy-
chloroquine for prophylaxis of SARS-CoV-2 infection for selected individuals
as follows:
• Eligible individuals:
• Asymptomatic healthcare workers involved in the care of suspected or confirmed
cases of COVID-19:
• 400 mg twice a day on Day 1, followed by 400 mg once weekly for next 7 weeks; to be taken
with meals
• Asymptomatic household contacts of laboratory confirmed cases:
• 400 mg twice a day on Day 1, followed by 400 mg once weekly for next 3 weeks; to be taken
with meals
34. • Invito studies for HCQ - SARS CoV 19
• 400 mg loading dose twice daily for 1 day, followed by a 200 mg maintenance
dose twice daily for 4 days
• Nonrandomized clinical trial of 20 patients found hydroxychloroquine
treatment to be significantly associated with viral load reduction and
disappearance in COVID-19 patients, with this effect increased by the
addition of azithromycin
• Hydroxychloroquine dosing was 600 mg daily, and azithromycin was 500 mg
on the first day followed by 250 mg daily for 4 days
• Found reduction of viral load in nasal swab at day 6
• Both drugs cause QT Prolongation-be carefull
35. • The statistics from retrospective analyses in China indicate that up to
30% of admitted patients required NIV, while early reports from Italy
indicate figures approaching 31%
• Equip with NIV as a stop gap to Invasive Ventilation
Editor's Notes
1. Walls AC, Park YJ, Tortorici MA, Wall A, McGuire AT, Veesler D. Structure, Function, and Antigenicity of the SARS-CoV-2 Spike Glycoprotein. Cell. 2020.
1. Walls AC, Park YJ, Tortorici MA, Wall A, McGuire AT, Veesler D. Structure, Function, and Antigenicity of the SARS-CoV-2 Spike Glycoprotein. Cell. 2020.
Figure 3. Visualization of 2019-nCoV with Transmission Electron Microscopy. Negative-stained 2019-nCoV particles are shown in Panel A, and 2019-nCoV particles in the human airway epithelial cell ultrathin sections are shown in Panel B. Arrowheads indicate extracellular virus particles, arrows indicate inclusion bodies formed by virus components, and triangles indicate cilia.
Envelope -anchored spike protein mediates coronavirus entry into host cells by first binding to a host receptor and then fusing viral and host membranes
Receptor -binding domain (RBD) of SARS -CoV spike specifically recognizes its host receptor angiotensin -converting enzyme 2 (ACE2)
susceptible to SARS -CoV infection is primarily determined by the affinity between the viral RBD and host ACE2 in the initial viral attachment step
R0 value (pronounced “R-naught”) - expected number of cases generated directly by 1 case in a population,
Figure 4. Schematic of 2019-nCoV and Phylogenetic Analysis of 2019-nCoV and Other Beta coronavirus Genomes. Shown are a schematic of 2019-nCoV (Panel A) and full-length phylogenetic analysis of 2019-nCoV and other beta coronavirus genomes in the Orthocoronavirinae subfamily (Panel B).
1. Giwa AL, Desai A, Duca A. Novel 2019 coronavirus SARS-CoV-2 (COVID-19): An updated overview for emergency clinicians. Emerg Med Pract. 2020;22(5):1-28.
1. Hellewell J, Abbott S, Gimma A, Bosse NI, Jarvis CI, Russell TW, et al. Feasibility of controlling COVID-19 outbreaks by isolation of cases and contacts. Lancet Glob Health. 2020;8(4):e488-e96.
1. van Doremalen N, Bushmaker T, Morris DH, Holbrook MG, Gamble A, Williamson BN, et al. Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. N Engl J Med. 2020.
1. Wang M, Cao R, Zhang L, Yang X, Liu J, Xu M, et al. Remdesivir and chloroquine effectively inhibit the recently emerged novel coronavirus (2019-nCoV) in vitro. Cell Res. 2020;30(3):269-71.
Yao X, Ye F, Zhang M, Cui C, Huang B, Niu P, et al. In Vitro Antiviral Activity and Projection of Optimized Dosing Design of Hydroxychloroquine for the Treatment of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Clin Infect Dis. 2020.
1. Gautret P, Lagier JC, Parola P, Hoang VT, Meddeb L, Mailhe M, et al. Hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an open-label non-randomized clinical trial. Int J Antimicrob Agents. 2020:105949.