COVID-19 Flashcards
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What are the genera within the Coronaviridae family?
(a) Alphacoronavirus
(b) Betacoronavirus
(c) Gammacoronavirus
(d) Deltacoronavirus
List three emergent Coronaviruses and their respective genera.
👑 MERS-CoV (Middle East Respiratory Syndrome Coronavirus): betacoronavirus
👑 SARS-CoV (Severe Acute Respiratory Syndrome Coronavirus): betacoronavirus
👑 SARS-CoV-2: betacoronavirus
SARS-CoV-2
(a) Order
(b) Family
(c) Genus
(d) Sub-genus
(a) Order: Nidovirales
(b) Family: Coronaviridae
(c) Genus: Betacoronavirus
(d) Sub-genus: Sarbecovirus
List four common Coronaviruses and their respective genera.
👑 Human coronavirus 229E (alphacoronavirus)
👑 Human coronavirus NL63 (alphacoronavirus)
👑 Betacoronavirus 1 (OC43) (betacoronavirus)
👑 Human coronavirus HKU1 (betacoronavirus)
Briefly discuss the structure of Coronaviruses [including the various protein components].
🛸 enveloped
🛸 Spike (S) proteins protrude form the viral envelope and are responsible for binding to host cell receptors.
🛸 Envelope (E) proteins embedded in the envelope are small proteins involved in virus assembly and release.
🛸 Membrane (M) proteins are the most abundant structural proteins, giving the virus its shape.
🛸 Nucleocapsid (N) proteins bind to the RNA genome, forming a helical structure.
[Diagram 1] [Diagram 2] [Diagram 3]
[Image 1] [Image 2] [Image 3]
What type of genome do Coronaviruses have?
single strand, positive-sense RNA
What is the primary receptor for SARS-CoV-2?
ACE2 (angiotensin-converting enzyme 2) receptor
Briefly discuss SARS-CoV-2 transmission pathogenesis.
Transmission:
👑 The virus primarily enters the body through respiratory droplets when an infected person coughs, sneezes, or talks.
Pathogenesis:
👑 The virus begins to replicate in the cells lining the nasopharynx and oropharynx.
👑 This initial replication can cause symptoms like sore throat and nasal congestion.
👑 The virus then spreads down the respiratory tract to the bronchi and eventually to the lungs.
👑 This can lead to more severe respiratory symptoms such as cough and shortness of breath.
👑 In the lungs, the virus specifically targets type 2 pneumocytes, which are cells responsible for producing surfactant to keep the alveoli (air sacs) open. The destruction of these cells impairs gas exchange and leads to respiratory distress.
👑 The immune response to the infection causes inflammation in the lung tissue.
👑 Inflammatory processes increase vascular permeability, leading to fluid leakage into the alveoli.
👑 Chronic inflammation can result in fibrosis (scarring) of lung tissue, further impairing lung function.
👑 The damage to the alveoli and fluid accumulation reduce the lungs’ ability to oxygenate the blood, leading to hypoxia (low blood oxygen levels).
👑 This can cause widespread inflammation, leading to septic shock, characterized by dangerously low blood pressure and organ failure.
👑 This can cause symptoms such as cyanosis (bluish discoloration of the skin), confusion, and fatigue.
👑 The virus and the immune response can damage both the epithelial cells lining the airways and the endothelial cells lining the blood vessels.
👑 This damage can lead to further leakage of fluid and proteins into the lung tissue.
👑 In severe cases, the immune response can become dysregulated, leading to a massive release of cytokines (cytokine storm).
👑 This can cause widespread inflammation, leading to septic shock, characterized by dangerously low blood pressure and organ failure.
Briefly outline signs and symptoms of SARS-CoV-2 infection, categorizing them into common, less common and emergency signs.
(a) Common signs
fever, cough, fatigue
(b) Less common
chills, sorethroat, headache, muscle aches, diarrhoea, nausea/vomiting, runny nose, loss of smell, loss/change in taste
(c) Emergency signs
difficulty in breathing, persistent chest pain, confusion, cyanosis, loss of consciousness
List risk factors for severe Covid-19.
Age > 60, Coronary Artery Disease, Stroke, Diabetes, Hypertension, Cancer, Chronic Lung Disease, Frailty, Pregnancy, Immunosuppression, Chronic Kidney Disease, Obesity
Briefly discuss the stages of Covid-19.
(1) Incubation Period
Duration: Typically 2-14 days after exposure, with an average of 5-6 days.
(2) Early Stage (Days 1-7)
Initial symptoms often include fever, dry cough, fatigue, sore throat, and muscle aches. Some people may experience loss of taste or smell, nasal congestion, or gastrointestinal symptoms like diarrhea.
(3) Pulmonary Stage (Days 7-12)
Symptoms can worsen, leading to difficulty breathing (dyspnea), persistent chest pain, and increased cough. Some patients may develop pneumonia.
(4) Hyperinflammatory Stage (Days 10-14)
The immune system’s overreaction can cause a cytokine storm, leading to widespread inflammation and multi-organ damage.
This stage can result in septic shock, organ failure, and increased risk of death.
(a) What is long COVID?
(b) List common symptoms of long COVID.
(a) This is a condition where symptoms last for at least three months after the initial COVID-19 infection.
(b) Symptoms:
General: fatigue, fever
Respiratory/Heart: difficulty breathing, shortness of breath, cough, chest pain, heart palpitations
Neurological symptoms: brain fog, headaches, sleep problems, dizziness, changes in smell/taste
Digestive: diarrhea, stomach pain, constipation
Briefly discuss sample collection and testing methods for diagnosis of COVID-19.
Sample collection: a nasopharyngeal or oropharyngeal swab is taken
Testing methods:
(1) PCR
(2) Rapid tests for antigens
(3) Sequencing
(4) Imaging: a chest X-ray may be done to show lung abnormalities such as infiltrates or consolidation.
Briefly discuss supportive treatment measures of COVID-19.
👑 Antipyretics/Analgesics: Used to reduce fever and relieve pain.
👑 Oxygen Therapy: Administered to patients with low oxygen levels to maintain adequate oxygenation.
👑 Anticoagulation Therapy: Given to hospitalized patients to prevent blood clots.
👑 Immunomodulation: Includes the use of steroids (e.g., dexamethasone) and anti-IL6 agents (e.g., tocilizumab) to modulate the immune response.
👑 Monoclonal Antibodies: Target the SARS-CoV-2 virus to neutralize it and prevent severe disease progression.
👑 Fluid/Electrolyte Therapy and Renal Care: Ensures proper hydration and kidney function.
👑 Antibiotics: Used when bacterial superinfection is suspected.
👑 Mechanical Ventilation: For patients with severe respiratory failure.
👑 ECMO (Extra-corporeal Membrane Oxygenation): Used in critical cases to provide cardiac and respiratory support.
