Updated: 1/19/2022


Review Topic
  • A 68-year-old man presents to the emergency department with cough and shortness of breath. The patient reports going to an urgent care approximately 2 weeks ago for abdominal pain. He has a medical history of hypertension, hyperlipidemia, and severe asthma. His temperature is 101°F (38.3°C), blood pressure is 158/95 mmHg, pulse is 100/min, and respirations are 26/min with an oxygen saturation of 85% on 6L nasal cannula. The patient is subsequently intubated, and a CT of the chest demonstrates ground glass opacities, fine reticular opacities, and vascular thickening. A nasal swab is positive for SARS-CoV-2.
  • Overview
    • betacoronavirus that is designated as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19) 
      • a positive sense single-stranded RNA virus
    • SARS-CoV-2 is in the same subgenus as severe acute respiratory syndrome corona virus (SARS-CoV)
    • enters cells via the angiotensin-converting enzyme 2 receptors, especially on epithelium that line the respiratory tract
    • TMPRSS2 primes spike protein on SARS-CoV-2 for entry
    • the incubation period is thought to be 2-14 days post-exposure
    • illness severity of this infection ranges from mild to critical 
      • mild (~81% of cases)
        • no dyspnea
      • severe (~14%)
        • dyspnea
        • respiratory rate ≥ 30/min
        • hypoxia
      • critical (~5%)
        • respiratory failure
        • shock
        • multiorgan dysfunction
  • Epidemiology
    • incidence
      • United States cases 
      • worldwide cases 
    • risk factors
      • close contact with suspected or confirmed cases of COVID-19
      • residence or travel to areas with high incidence of COVID-19
  • Transmission
    • person-to-person transmission
      • thought to mainly occur via respiratory droplets
        • the virus can be released into the air when the infected person coughs or sneezes
        • the virus reaching the host's mucous membrane can result in infection
      • can also be transmitted longer distances via airborne route
        • studies suggest that droplets may get aerosolized and be carried > 6 ft (2 meters) with speaking, coughing, or sneezing
    • fomite transmission
      • touching an infected surface and subsequently touching one's eyes, nose, or mouth can result in infection
        • therefore, disinfectant is recommended
    • fecal-oral transmission
      • the SARS-CoV-2 RNA has been detected in stool, so fecal-oral transmission is possible
  • Prognosis
    • unfavorable factors
      • older age (≥ 65 years of age)
        • more likely to develop severe disease
      • chronic medical conditions
        • diabetes
        • cardiovascular disease
        • hypertension
        • chronic lung disease
        • chronic kidney disease
        • cancer
        • body mass index ≥ 30 kg/m2
      • immunocompromising conditions
        • transplant patients on immunosuppressant drugs
      • certain laboratory derrangements
        • ↑ D-dimer
        • ↑ ferritin and C-reactive protein
        • ↑ creatine phosphokinase
        • ↑ troponin
        • ↑ lactate dehydrogenase
        • ↑ prothrombin time
        • acute kidney injury
        • severe lymphopenia
  • Symptoms
    • fever (~99% of cases)
    • fatigue (~70%)
    • dry cough (~60%)
    • myalgias (~35%)
    • dyspnea (~30%)
    • sputum (~27%)
    • anosmia (10-50%)
    • patients may develop gastrointestinal symptoms
      • nausea (~12%)
      • diarrhea (~19%)
  • Chest CT
    • findings
      • ground-glass opacification (GGO)
        • consolidative abnormalities may or may not be present
        • more likely to affect both lungs, particularly in the lower lobes and in a peripheral distribution
  • Reverse-transcription PCR (RT-PCR) for SARS-CoV-2
    • procedure
      • collection of a nasopharyngeal swab
        • orophaygneal swab can also be collected (not essential)
      • sputum collection in patients with a productive cough
  • Serum labs
    • WBC count
      • variable (leukopenia, leukocytosis, and lymphopenia)
        • lymphopenia is more common
    • lactate dehydrogenase and ferritin level are commonly elevated
    • IL-6 may be elevated
COVID-19 Differential Diagnosis
Virus Fever Cough Fatigue Myalgia Headache Rhinitis Sore Throat
↑↑↑ ↑↑ Rare
Influenza ↑↑↑ ↑↑↑ ↑↑↑ ↑↑↑ ↑↑↑
Common cold Rare ↑↑↑ ↑↑ ↑↑↑ ↑↑↑
  • A registry of clinical trials can be found here  
    • lopinavir-ritonavir 
      • a combined protease inhibitor
    • remdesivir 
      • a novel nucleotide analog that impairs RNA-dependent polymerases
    • IL-6 pathway inhibitors
      • tocilizumab 
      • siltuximab 
      • sarilumab 
  • Medical
    • supportive care and quarantine
      • indications
        • for mild cases patients are quarantined to their homes and symptomatically managed
    • hospitalization with potential oxygen supplementation or mechanical ventilation
      • indications
        • for severe disease, characterized by hypoxia (O2 saturation ≤ 94% on room air), an oxygen requirement, or ventilatory support
          • hospitalized patients with severe disease but not yet on oxygen supplementation
            • remdesivir only
          • hospitalized patients with severe disease who are receiving supplemental oxygen (including high-flow oxygen and non-invasive ventilation)
            • low-dose dexamethasone AND remdesivir
          • hospitalized patients with severe disease who require mechanical ventilation
            • low-dose dexamethasone only
  • Hygiene and isolation should be in accordance with state and local health department recommendations and regulations
  • Hand hygiene
    • should be washed with water and soap or virucidal hand disinfectant
    • avoid face touching
  • Respiratory hygiene
    • maintain 6 feet of distance from others
    • masks (N95 respirators) and face shields or goggles for health care personnel or persons taking care of infected individuals in a health care facility or home
  • Face coverings
    • the CDC and WHO recommend wearing masks when in public spaces and when in the presence of individuals outside of one's household 
  • Social and physical distancing 
    • Avoidance of crowds and non-essential travel 
  • Screening for infection in high-risk settings (e.g. nursing facilities, college campuses, hospital employees)
    • testing-based screening is advantageous compared to symptom-based screening in that it allows identification of asymptomatic infections
  • Vaccines
    • primary antigenic target: surface spike protein
    • multiple vaccine candidates have shown efficacy without major adverse effects in early-phase human clinical trials
    • two mRNA vaccines have over 95% vaccine efficacy in preventing symptomatic COVID-19
      • BNT162b2 (Pfizer-BioNTech) COVID-19 mRNA vaccine
        • two intramuscular injections administered 3 weeks apart
      • mRNA-1273 (Moderna) COVID-19 mRNA vaccine
        • two intramuscular injections administered 4 weeks apart
  • Acute respiratory distress syndrome
    • has been associated with
      • older age (≥ 65 years of age)
      • diabetes mellitus
      • hypertension
  • Pneumonia
  • Septic shock
  • Cardiac arrhythmia
  • Cardiac injury
  • Note, this page is not meant to diagnose or treat patients but more as an evolving source of information
  • For more information, please see the following sources
    • Center for Disease Control 
    • National Institutes of Health 
    • World Health Organization 

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