Table 1.
Differences between SARS, MERS, and SARS-CoV-2.
| SARS-CoV16,31,32 | MERS-CoV31, 32, 33 | SARS-CoV-216,31,34,35 | |
|---|---|---|---|
| First occurrence | November 16, 2002, in Foshan, Guangdong | September 2012 | December 7, 2019, in Wuhan, Hubei |
| Virus type | RNA virus | ||
| Species pathogen | Beta-coronavirus | ||
| Intermediate host | Paguma larvata | Dromedary camel | Pangolin, mink, bat (possible) |
| Definitive host | Rhinolophus sinicus | Tylonycteris pachypus and Pipistrellus abramus | Rhinolophus sinicus (possible) |
| Predominant receptor | Human ACE2 | Human DPP4 (or CD26) | Human ACE2 |
| Total DNA sequence length of pathogen | 29,751 | 30,119 | 29,903 |
| Characteristic gene order | 50-replicase ORF1ab, spike (S), envelope (E), membrane (M), and nucleocapsid (N)-30 | 5′-Replicase ORF1ab-S-envelope (E)-membrane (M)-nucleocapsid (N)-3′; ORF3ab, ORF6, ORF7ab, ORF8, ORF9ab, and ORF10 | |
| Transmission rate | More than MERS-CoV but less than SARS-CoV-2 | Less than SARS-CoV and SARS-CoV-2 | More rapid than MERS-CoV and SARS-CoV |
| Male–female patient ratio | 1.0:1.2 | — | 2.7:1.0 |
| Clinical symptoms | Fever, cough, myalgia, dyspnea, and diarrhea | High fever, chill, cough, shortness of breath, chest pain, headache, myalgia, sore throat, arthralgia, abdominal pain, anorexia, vomiting, and severe diarrhea (some cases) | Fever, fatigue, and dry cough |
| Propagation mode | Droplets or close contacts, fomites, fecal transmission, and handling of animals having the virus | Droplets or close contact with infected dromedary camels | Human to human/spread through respiratory droplets from coughs or sneezes; handling of animals having the virus |
| Diagnostic methods | real-time PCR (RT-PCR), rRT-PCR, RT-LAMP, rRT-LAMP, coronavirus detection kit | Chest radiography, electron microscope, immunofluorescence microscopy, cell culture, enzyme-linked immunosorbent assay (ELISA), and RT-PCR | RT-PCR, rRT-PCR, RT-LAMP, rRT-LAMP, coronavirus detection kit |
| Treatment | Glucocorticoid and interferon | Interferon, lopinavir/ritonavir, cyclosporin A, chloroquine/hydrochloroquine | Lopinavir/ritonavir, chloroquine |
| Mortality | 9.6% | 40.0% | 2%–7% |
| Number of deaths worldwide | 916 | 800 | 379,941 and rising daily (WHO website, June 3, 2020) |
rRT, reverse transcription loop-mediated isothermal amplification; rRT-LAMP, real-time reverse transcription LAMP assay.