COVID-19 Overview and Transmission Risks

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Questions and Answers

What type of virus is SARS-CoV-2?

Double-stranded RNA virus

Single-stranded DNA virus

Double-stranded DNA virus

Single-stranded RNA virus (correct)

Which receptor does the spike protein of SARS-CoV-2 bind to on host cells?

Insulin receptor

ACE2 receptor (correct)

IgG receptor

CD4 receptor

What is one characteristic of a cytokine storm associated with COVID-19?

Significant immune suppression

Increased production of erythropoietin

Elevated levels of IL-6 (correct)

Decreased IL-6 levels

Which group is more at risk for severe COVID-19 disease based on age and gender?

Older adults and males Signup and view all the answers

What mechanism allows SARS-CoV-2 to evade the early immune response?

Delaying the Type I interferon response Signup and view all the answers

Which of the following is NOT a method of transmission for SARS-CoV-2?

Latent infection Signup and view all the answers

Which condition is considered a risk factor for severe COVID-19 disease?

Hypertension Signup and view all the answers

Emerging infectious diseases are defined as:

Newly identified or re-emerging diseases Signup and view all the answers

What is a significant factor in the emergence of infectious diseases (EIDs)?

Zoonotic transmission Signup and view all the answers

Which animal is linked to the transmission of SARS-CoV-1 to humans?

Civet cats Signup and view all the answers

What mechanism is often involved in the pathophysiology of viral infections?

Viral replication and immune evasion Signup and view all the answers

How are respiratory diseases such as COVID-19 primarily transmitted?

Airborne droplets and fomite transmission Signup and view all the answers

What contributes to increased zoonotic spillover risk?

Climate change and deforestation Signup and view all the answers

Who is at increased risk for infections by emerging infectious diseases?

Healthcare workers treating infected patients Signup and view all the answers

Which pathogen is associated with causing a cytokine storm?

Ebola virus Signup and view all the answers

What role does global travel play in the transmission of emerging infectious diseases?

It facilitates the spread of EIDs. Signup and view all the answers

What is the primary transmission method for COVID-19?

Droplets and surfaces Signup and view all the answers

Which of the following correctly describes the pathophysiology of the Ebola virus?

Causes a cytokine storm Signup and view all the answers

Which risk factor is associated with MERS-CoV infection?

Exposure to camels Signup and view all the answers

What is a common transmission method for Hantavirus?

Inhalation of rodent urine/feces Signup and view all the answers

Which virus is primarily associated with causing microcephaly in infants?

Zika virus Signup and view all the answers

What is a key risk factor for contracting COVID-19?

Age over 65 years Signup and view all the answers

Which characteristic is true of SARS-CoV?

It binds to ACE2 receptors Signup and view all the answers

Which of the following viruses is zoonotic and associated with animal contact?

Hantavirus Signup and view all the answers

Study Notes

COVID-19

Caused by SARS-CoV-2, a single-stranded RNA virus
Coronavirus family, crown-like appearance due to spike (S) glycoproteins
Binds to ACE2 receptors on host cells via spike protein, activated by TMPRSS2
Virus releases RNA genome, replicates using host cell machinery, and releases new virions through exocytosis
Innate immune response delayed, allowing for replication before detection
Excessive immune activation (cytokine storm) leads to severe inflammation and lung damage (edema, ARDS)

Transmission

Person-to-person via respiratory droplets, direct contact, and contaminated surfaces
Touching the mouth, eyes, or nose after contact can transmit the virus
Virus can survive on surfaces

Risk Factors

Age (older adults) and gender (males) increase risk of severe disease
Comorbidities like obesity, diabetes, hypertension, cardiovascular disease, and chronic respiratory conditions increase risk
Certain ethnic groups have higher risk of hospitalization and mortality
Immunosuppression (HIV, organ transplants) impairs immune response increasing risk of severe disease

Emerging Infectious Diseases (EID)

Newly identified or re-emerging diseases with increased incidence or geographic range
Examples include Ebola, SARS, MERS, COVID-19, Zika virus, and Hantavirus

Zoonotic Transmission

Pathogens spill over from animals to humans
Zoonotic hosts include bats, camels, civets, and other wildlife
SARS-CoV-1 from civet cats
MERS-CoV from dromedary camels
COVID-19 (SARS-CoV-2) linked to animal reservoirs (likely bats)
EID pathophysiology varies, but often involves viral entry, replication, immune evasion, and inflammatory cytokine response

Pathophysiology

Entry via viral entry and replication
Host immune evasion
Cytokine-driven inflammation
Example: Ebola infection of dendritic cells and macrophages leads to immune evasion and cytokine storms
Example: SARS-CoV-2 involves ACE2 receptors, immune activation, and ARDS

Human-to-Human Transmission

Spread through direct contact, droplets, bodily fluids, and contaminated surfaces
Respiratory diseases like COVID-19 and SARS are spread via respiratory droplets and contaminated surfaces

Risk Factors for EIDs

Close contact with wild animals or their habitats
Frontline healthcare workers treating infected patients
Travel to outbreak regions
Climate change and deforestation bringing humans closer to wildlife reservoirs
Globalization and urbanization leading to increased human movement and dense populations facilitating transmission

Additional Conditions

SARS-CoV from civet cats: Binds to ACE2 receptors, Transmission via respiratory droplets and surfaces
Hantavirus (from rodents): Inhaled rodent urine/feces, possibly a rodent exposure risk.
Zika virus (Flavivirus family): Transmitted by mosquito bites, infection of neural progenitor cells leading to complications like microcephaly

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Description

This quiz covers key aspects of COVID-19, including its cause, transmission methods, and risk factors leading to severe disease. Learn about the SARS-CoV-2 virus, its replication process, and the impact of various health conditions on COVID-19 severity.