This summary article is intended to be used as a quick reference guide. Please see our complete COVID-19 article for more detail.
COVID-19 (coronavirus disease 2019) is a viral infectious disease caused by SARS-CoV-2 and is currently a World Health Organization (WHO) declared pandemic. As of January 2021, over 90 million people had been infected globally with over 1.9 million deaths .
Many people with SARS-CoV-2 infection are asymptomatic . Symptoms and signs of COVID-19 are non-specific but in symptomatic individuals most commonly include:
- fever (85-90%)
- cough (65-70%) with sputum in 30-35%
- smell and taste disturbances (50%)
- fatigue (35-40%)
- shortness of breath (15-20%)
The likelihood of severe illness requiring hospitalization correlates closely with male sex, advanced age and presence of comorbidities.
- ~5% admitted patients require ICU admission
Multiple serious sequelae have been reported including:
- acute respiratory distress syndrome (ARDS)
- coagulopathy: including PE and DIC
- secondary infections, e.g. bacterial pneumonia
- acute kidney injury (AKI)
- multiorgan failure
- secondary hemophagocytic lymphohistiocytosis
SARS-CoV-2 is a member of the Betacoronavirus genus, one of the genera of the Coronaviridae family of viruses. SARS-CoV-2 is indirectly zoonotic, but transmission is now primarily interhuman. The closest animal coronavirus by genetic sequence is a bat coronavirus . The cause of death is usually respiratory failure secondary to massive alveolar injury.
The primary findings of COVID-19 are those of atypical or organizing pneumonia . Up to 18% of cases demonstrate normal chest x-rays or CT when mild/early in the disease course . Bilateral and/or multilobar involvement is common, more often with a lower zone distribution.
- patchy or diffuse airspace opacities, whether consolidation or ground-glass opacity
- pleural effusion is rare
The primary findings on CT in adults have been reported as :
- ground-glass opacities (GGO)
- crazy paving appearance (GGOs with inter-/intra-lobular septal thickening)
- air space consolidation
- bronchovascular thickening in the lesion
- traction bronchiectasis
Treatment and prognosis
Treatment is primarily supportive including ventilation for some patients. Dexamethasone has been shown to reduce mortality in ventilated patients or those on oxygen therapy .
An mRNA-based vaccine recently received regulatory approval in several territories .
The mortality rate is estimated to be 3.6% .