Background
Genus | Clade I, lineage B | Clade I, lineage B | Clade II, lineage C |
Length of nucleotides | 29.9 kilobases | 29.75 kilobases | 30.11 kilobases |
First emergence | 7 December 2019, Wuhan, China | 16 November 2002, Foshan, China | 4 April 2012, Zarqa, Jordan |
Virus identification | January 2020 | March 2003 | June 2012 |
Causative agent declaration | January 2020 | April 2003 | September 2012 |
Recent status | Pandemic ongoing | Completely control | Sporadic continuous |
Number of infected cases | Above 12.7 milliona | 8096 | 2553 |
Male-to-female ratio | 1.27:1 | 1:1.13 | 1.78:1 |
Number of attributed deaths | Above 566 thousanda | 774 | 876 |
Number of viral Footprint | 213 countries or regionsa | 29 countries or regions | 27 countries or regions |
Case fatal rate | 4.4% | 9.6% | 34.3% |
Traits of SARS-CoV, MERS-CoV, and SARS-CoV-2
Animal hosts
Morphology and genome organization
Cellular entry and viral transmission
Cytokine and chemokine responses
Features of SARS, MERS and COVID-19
Demographic characteristics
Signs and symptoms | |||
Fever | 56–99% | 99–100% | 81.7–100% |
Fatigue | 18–55% | 31.2% | NA |
Cough | 39–81% | 29.0–74.3% | 75–85% |
Sore throat | 5–17% | 11.0–23.2% | 14 |
Dyspnea | 12–41% | 40–42% | 72% |
Myalgia | 18–55% | 49.3–60.9% | 38 |
Diarrhea | 3–17% | 20–25% | 26 |
Headache | 4–23% | 15.0–55.8% | NA |
Complications | |||
ARDS | 18–30% | 20% | 20–30% |
AKI | 3% | 6.7% | 41–50% |
Laboratory findings | |||
Leukopenia (< 4.0 × 109/L) | 26.8% | 23–35% | 14% |
Lymphopenia (< 1.5 × 109/L) | 55.3% | 68–85% | 32% |
Thrombocytopenia (< 150 × 109/L) | 11.5% | 40–45% | 36% |
Elevated LDH | 55.5% | 50–71% | 48% |
Elevated AST | 17.9% | 20–30% | 14% |
Elevated ALT | 16.0% | 20–30% | 11% |
Incubation period and clinical manifestations
Laboratory tests
Chest radiology
Image performance | Bilateral, multifocal, peripheral distribution | Unilateral, focal; unilateral, multifocal; bilateral; peripheral distribution | Bilateral, multifocal; isolated unilateral; peripheral distribution |
Normal radiography | 19.90% | 18.40% | 20.00% |
Abnormal radiography | |||
Ground-glass opacities | 68.92% | 68.48% | 86.36% |
Crazy paving pattern | 8.56% | 46.27% | 26.67% |
Consolidation | 26.64% | 65.65% | 50.00% |
Interlobular septal thickening | 34.54% | 55.22% | 40.91% |
Air bronchogram | 34.54% | 37.04% | NA |
Pleural effusion | 3.57% | 17.31% | 54.55% |
Pneumothorax | Rare | 9.62% | Rare |
Centrilobular nodules | Not seen | Not seen | Not seen |
Cavitation | Not seen | Not seen | Not seen |
Lymphadenopathy | 6.00% | Not seen | Not seen |
Pulmonary pathology
Gross examination | Diffuse congestions with partly hemorrhagic necrosis | Edematous lungs with diffuse congestion, enlarge pulmonary hila lymph nodes, irregular and patchy consolidation areas | Edematous lungs with consolidation |
Microscopic manifestation | Main abnormalities: 1. Early-stage: exudative DAD without hyaline membrane formation; 2. Advanced-stage: DAD with hyaline membrane formation; Others: pleural effusion and adhesion, mucous plugs formation, macrophages, neutrophils and lymphocytes infiltration; microvascular injury (microthrombi) | Main abnormalities: 1. Acute-period: acute exudative DAD (extensive edema and hyaline membrane formation, alveolar epithelial cells impairment, alveoli collapse, and fibrous tissue in alveolar spaces); 2. Progress-period: Combination of acute exudative DAD and proliferative DAD (fibrinous interstitial and airspace and hyperplastic pneumocytes); Others: intravascular microthrombi | Main abnormalities: Acute exudative DAD with focal hemorrhagic necrotizing pneumonia (dispersed necrotic debris); Others: NA |
Superinfection | Bacteria | Bacteria, fungi, viruses | NA |