Coronavirus Disease 2019 (COVID-19) – At A Glance

COVID-19 is a disease caused by SARS-CoV-2 which lead to a global pandemic in 11th March 2020. 

Previously it was called as novel coronavirus (2019-nCoV)

Origin 

    • Corona virus is an organism that typically present in animals (Mammals, birds) – Bats
    • When mutations occur these viruses have the ability to infect other species
    • In this case, it is believed that it was transmitted to pangolins
    • Pangolins are the most common illegally trafficked mammal
    • In pangolins, these viruses have developed new mutations to infect humans
    • As these pangolins are distributed all around the globe, the virus also spread throughout the world infecting the human population 
    
Transmission   

    • Droplet transmission 
          By airborne respiratory droplets produced by sneezing and coughing
          These droplets can usually travel up to 6 feet
    • Contact transmission
          Person touches a contaminated surface and touches their mouth, nose and eyes    
          Transmission occurs through mucous membranes
    • Aerosol transmission
          Respiratory droplets mixes with air to form aerosols
          Can cause infection when inhaled in large doses
    • Feco-oral transmission    
 


High risk group for severe disease
    • People 65 years and older
    • People who live in a nursing home or long-term care facility
    • People with underlying medical conditions which are not well controlled 
          Chronic lung diseases
          Cardiovascular diseases
          Immunocompromised patients (HIV, steroids, malignancy, smoking)
          Morbid obesity 
          Hypertension
          Diabetes mellitus 
          Chronic kidney disease
          Chronic liver disease
    
Pathophysiology
Contact of airborne droplets
            ↓ 
Enter the respiratory system – Alveoli
            ↓ 
Attach to specific receptors (ACE-2) on type-2 pneumocytes using spike proteins on the cell surface of the virus
            ↓ 
Virus is engulfed into the cell
            ↓ 
Release the viral single stranded RNA into the cytoplasm of the cell
            ↓ 
Transcription and translation of viral gnome
            ↓ 
Virion is assembled within the cytoplasm & release from the cell
            ↓ 
Attracts neutrophils and macrophages – Initiating a inflammatory process
            ↓ 
Release cytokines (IL-1, IL-6, TNF α)
Further attacks neutrophils leading to more and more damage → Cytokines enter into the blood stream 
            ↓                                                                                         
Damage to alveoli                             
Vasodilatation                                            
Increase vascular permeability         
            ↓                                                      
Alveolar oedema                               
Alveolar collapse                                
Hypoxaemia                                            
            ↓                                                                                               
Tachypnoea
 
Clinical presentation 
    • Presentation can range from asymptomatic to severe disease
    • Symptoms can occur from 2 days to 2 weeks following exposure
    • History of recent contact and travel is of immense value 
 
    Commonest presentations 
        • Cough 
        • Difficulty in breathing / Shortness of breath
        • Fever ± chills
        • Sorethroat
    Associated features
        • Sputum 
        • Malaise 
        • Nausea
        • Diarrhoea
        
Complications
    • Pneumonia
    • ARDS (Acute respiratory distress syndrome)
    • Cardiac injury 
    • Arrhythmia
    • Septic shock 
    • Organ dysfunction – Liver, Kidney 
    • Multiorgan dysfunction
    
Investigations
    • First do nasophayngeal swab to exclude influenzae 
    • RT-PCR 
        Samples – Nasal swab, bronchoalveolar lavage, sputum, serum samples
    • Antibody tests for SARS-CoV-2 – Done only in emergency cases
    • Complete blood count – Lymphopenia
    • ESR. CRP – Elevated 
    • Liver function tests (Elevated AST, ALT)
    • Renal function tests (Elevated BUN, S. creatinine)
    • Imaging
        • Chest X-ray – Ground glass appearance (Intestitial oedema)
        • CT scan – Best
             Ground glass appearance
             Consolidation
             Peripheral distribution
 
Treatment    
    Home management
        • Self quarantine for 14 days
              In suspected exposure
              When a person develops fever, cough, sorethroat, shortness of breath
        • Antipyretics – Paracetamol to control fever
        • Proper hydration
        • If symptoms are worsening  Immediately reach out to the nearest hospital 
        
    Hospital management
        • Assess and correction of hydration status
              Use IV fluids if necessary 
              Unnecessary use of IV fluids can worsen intestitial oedema
        • Antipyretics – Paracetamol (Avoid Ibuprofen – Can worsen the condition)
         Continuous monitoring of the patient
              Vital signs (Pulse, BP, temperature)
              Respiratory rate
              Oxygen saturation
              Urine output 
         If patient is critical, transfer the patient to ICU / HDU as they might require ventilatory support 
        • Remdesivir
              Broad-spectrum antiviral agent
              Previously used in the treatment of Ebola
              It interferes with the action of viral RNA-dependent RNA polymerase to reduce the viral RNA production 
        • Chloroquine / Hydrochloroquine
              Antimalarial agent
              It disrupts the ability of the virus to enter type-2 pneumocytes 
        • Other investigational drugs 
              Ritonavir – Antiretroviral agent
              Ivermectin – Antiparasitic agent
              Tocilizumab – IL-6 inhibitor
              Corticosteroids
              Immunomodulators 
 
Prevention 
    • No vaccine is available yet 
    • Hand-washing with soap and water for at least 20 second
    • Avoid touching their eyes, nose, and mouth with unwashed hands
    • Avoid close contact with sick people
    • Self isolation if an individual become symptomatic
    • Cover coughs and sneezes with tissues followed by proper disposal
    • Prevention of community spread
          Self isolation, if an individual become symptomatic
          Avoid unnecessary travels and stay at home during the pandemic 
          Practicing social distancing (Maintaining a distance of 6 feet from other persons) 
          People with increased risk of infection should self quarantine themselves for 14 days
              Close contact with a person suspected / known case of COVID-19
              International travelers
              Health workers
          Use of facemasks ± gloves 
          Take legislative actions to prevent community / social gatherings 
          Health education and health promotion through media to keep the community updated 
     Identify and reduce transmission from the animal source
 
Research Facts 
• Mild COVID-19 disease has a higher rate of false negative results in viral RT-PCR test
    • Increased severity of the disease, increases the sensitivity of viral RT-PCR test
    • Bonchoalveolar lavage has a higher sensitivity than pharyngeal aspirate 
    • Surgical facemask for infected patients can reduce transmission of the disease 
    • N95 respirators does not have a significant advantage over surgical facemasks    
    • Asymptomatic patients can transmit the disease
    • Incubation period is 5 – 6 days up to 14 days 
    • Fatality rate is 2%
    • BCG vaccination which is given at birth reduces the severity of the illness
    • Very susceptible to high heat (70°C)
    • SARS-CoV-2 virus can survive….
          On copper : Up to 4 hours
          On paper : Up to 24 hours
          On glass : Up to 4 days
          On plastic and stainless steel : Up to 7 days
    • Infected patients passes the virus through their feces leading to feco-oral transmission 
Latest posts by Dr. Janani Rajamanthri (see all)
5 1 vote
Article Rating
Subscribe
Notify of
guest
2 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
Jenna Salma
Jenna Salma
1 year ago

Thank you so much ❤️ it is very descriptive

Leo gamininga
Leo gamininga
1 year ago

how much time it takes for a person to recover after becoming infected?