Table 1.
Comparison of the characteristics, pathophysiologies and management of viral pandemics.
| SARS-CoV-2 | SARS-CoV | MERS-CoV | Ebola | H1N1 | HIV | References | |
|---|---|---|---|---|---|---|---|
| Outbreak year and location of first reported cases | 2019 (Wuhan, China) | 2003 (Southern China) | 2012 (Saudi Arabia) | 1976 onwards (Central Africa) | 2009 (North America) | 1981 onwards (West Central Africa) | [172] |
| Outbreak countries | More than 215 countries, including the USA, India, Brazil, China, Japan, Korea, Italy, etc. | 29 countries, including China, Vietnam, Singapore and Canada | More than 27 countries, mainly in Saudi Arabia, South Korea, Jordan and Qatar | Africa, the Americas, South East Asia, Europe, Eastern Mediterranean, Western Pacific | Africa, Europe, the Americas, South-East Asia | More than 130 countries, including the USA, China, India, etc. | [173,174] |
| Natural reservoir | Not identified | Bat | Bat | Fruit bats, porcupines and non-human primates | Human, avian, swine | Chimpanzee | [173,175] |
| Receptor | ACE2, TMPRSS2, sialic acid |
ACE2, CD206, sialic acid |
DPP4 (CD26), sialic acid |
TIM1 (NPC1) | sialic acid | CD4 | [79,80,81,176,177,178] |
| Case Fatality Rate | Not identified, at least 2–3% | 10% | 34.4–37% | 50–63% | 0.02–0.4% | 80–90% | [179,180] |
| Hospitalization rate | ~19% | Most cases | Most cases | 25–90% | 16.19–58.76% | >34.2% | [181,182,183] |
| Community attack rate | 30–40% | 10–60% | 4–13% | 5–30% | 10–20% | 23% | [184] |
| Basic reproductive number (R0) | 1.4–6.4 | 2–5 | <1 | 1.9 | 1.3 | 2–5 | [179,185] |
| Median incubation time | 5.2 days | 5 days | 5 days | 2-21 days | 1–7 days | 5–70 | [186,187] |
| Clinical symptoms | Fever (98%), cough (77%), dyspnea (63.5%), myalgia (11.5%), malaise (35%) and so on | Fever (>99%), cough (62%–100%), chills or rigor (15%–73%), diarrhea 20%, dyspnea (40%) | Fever (77%), cough (90%), dyspnea (68%), sputum production (40%), odynophagia (39%), digestive system/signs (20%), hemoptysis (4.3%), myalgia (43%) and headache (20%) | Fever, fatigue, muscle, pain, headache, sore throat, vomiting, diarrhea, rash, kidney and liver impairments and, in some cases, internal and external bleeding (e.g., oozing from the gums, blood in the stools). Laboratory findings include low WBCs and platelet counts and elevated liver enzymes. | Fever, chills, cough, sore throat, runny or stuffy nose, red eyes, body aches, headache, fatigue, diarrhea, nausea and vomiting | Muscle aches (85%), fatigue (84%), bloating (82%), fever (79%), headache (73%), memory loss (73%), cough (74%), poor appetite (74%), diarrhea (71%) and nausea (72%) | [50,182,188,189,190] |
| Radiology | Critically ill with bilateral multiple lobular and subsegmental areas of consolidation; mild ill with bilateral ground-glass opacity and subsegment alareas of consolidation, almost 100% of patients with abnormal CT |
Unilateral/bilateral ground-glass opacities or focal unilateral/bilateral consolidation. The rate of abnormal chest radiography or CT was >94% | Unilateral/bilateral patchy densities or infiltrates, bilateral hilar infiltration, segmented/lobar opacities, ground-glass opacities and possible small pleural effusions. The rate of abnormal chest radiography or CT was between 90% and100% | Aerosolized virus would be unlikely to produce discrete, radiographically visible, pulmonary lesions. | Initial chest radiographs show central or peripheral pulmonary GGO and consolidations with patchy or nodular appearance; multizonal and bilateral peripheral opacities are associated with adverse prognosis. | Bronchiectasis, with ill-defined centrilobular micronodularity and branching structures to mucous impaction in the bronchioles, along with cavitation. | [186,191,192] |
| Cytokines | Increased levels of IL-1β, IL1RA, IL-7, IL-8, IL-9, IL-10, basic FGF, GCSF, GMCSF, IFN-Ɣ, IP10, MCP1, MIP1α, MIP1β, PDGF, TNF-α and VEGF; Critically ill patients have high levels of GCSF, TNF-α and Th2 cytokines (e.g., IL-4 and IL 10) | Increased levels of IL-1β, IL-6, IL-12, IFN-Ɣ, IP10 and MCP-1 | Increased concentrations of proinflammatory cytokines (IFN-Ɣ, TNF-α, IL-15 and IL-17) |
TNF-α, IFN-γ, IL-1RA, IL-6, IL-15, MIG, MIF, MIP-1α, MIP-1β, MCP-1, IP-10, ITAC, eotaxin, IL-2, IL-1β, IL-8, HGF, VEGF, GM-CSF and G-CSF | IL1RA, IL-6, TNF-α, IL-8, MCP-1, MIP1β and interferon-inducing protein-10 | Increased levels of TNF-α, TNF-β, IFN-Ɣ, IL-1, IL-2, IL-6, IL-7, IL-10, IL-13, IL-15 and IL-16 | [148,186,193,194,195] |
| Treatment | Corticosteroids, remdesivir, combination of lopinavir and ritonavir, type I interferon and so on | Lopinavir and ritonavir, corticosteroids, IFN-Ɣ, IVIG | IFN-Ɣ, lopinavir and ritonavir, mycophenolic acid | During the 2018 eastern Democratic Republic of the Congo outbreak, two out of four investigational treatments initially available to treat patients with confirmed Ebola, are still in use. These two are REGN-EB3 and mAb114. In addition, treatments include fluid intake and intravenous electrolytes, oxygen therapy and using medication to manage blood pressure, vomiting, diarrhea, fever and pain. | Oseltamivir (Tamiflu),peramivir (Rapivab) andzanamivir (Relenza) appeartowork best, although some types of swine flu do not respond to oseltamivir. | Anti-retroviral therapy, which includes medications such as abacavir, efavirenz, enfuvirtide, atazanavir, maraviroc, dolutegavir, ibalizumab, cobicistat, etc. | [180,196,197,198] |
ACE2: Angiotensin-converting enzyme 2; CD: Cluster of differentiation; CT: Computed tomography; DPP4: Dipeptidyl peptidase IV; FGF: Fibroblast growth factor; G-CSF: Granulocyte colony-stimulating factor; GGO: Ground-glass opacities; GM-CSF: Granulocyte/monocyte colony-stimulating factor; H1N1: Influenza virus A subtype H1N1; HGF: Hepatocyte growth factor; HIV: Human immunodeficiency virus; ICU: Intensive care unit; IFN: Interferon; IL: Interleukin; IL1RA: Interleukin-1 receptor antagonist; IP: Interferon γ-induced protein; ITAC: Interferon-inducible T-cell α chemoattractant; IVIG: Intravenous immunoglobulin; mAb114: Monoclonal antibody 114; MCP: Monocyte chemoattractant protein; MERS-CoV: Middle-East respiratory syndrome coronavirus; MIF: Macrophage migration inhibitory factor; MIG: Monokine induced by gamma; MIP: Macrophage inflammatory protein; NPC1: Neimann-Pick C1 protein; PDGF: Platelet-derived growth factor; REGN-EB3: cocktail of three monoclonal antibodies REGN3470, 3471 and 3479 developed by Regeneron Pharmaceuticals; SARS-CoV: Severe acute respiratory syndrome coronavirus; SARS-CoV-2: Severe acute respiratory syndrome coronavirus 2; Th2: T-helper cell type-2; TIM1: T-cell immunoglobulin and mucin domain 1; TMPRSS2: Transmembrane serine protease 2; TNF: Tumour necrosis factor; VEGF: Vascular endothelial growth factor; WBC: white blood cell.