Table.
Comparison of characteristics of SARS, MERS, and COVID-19a
| Characteristics | SARS | MERS | COVID-19 |
|---|---|---|---|
| First patients reported | Guangdong, China, November 2002 | Zarga, Jordan, April 2012, and Jeddah, Saudi Arabia, June 2012 | Wuhan, China, December 2019 |
| Virus | SARS-CoV | MERS-CoV | SARS-CoV-2 |
| Type of coronavirus | Betacoronavirus | Betacoronavirus | Betacoronavirus |
| Host cell receptor | Angiotensin converting enzyme 2 | Dipeptidyl peptidase 4 | Structural analysis suggests angiotensin converting enzyme 2 receptor52 |
| Sequence similarity | Reference | 79% to SARS-CoV, 50% to MERS-CoV35 | |
| Animal hosts | Bats (natural reservoir), masked palm civet and raccoon dogs may be intermediate hosts | Bats (natural reservoir), dromedary camel (intermediate host) | Bats, animals sold at the seafood market in Wuhan might represent an intermediate host35 |
| Incubation period | |||
| Mean (95% CI, d) | 4.6 (3.8–5.8) | 5.2 (1.9–14.7) | 5.2 days (95% confidence interval [CI], 4.1–7.0); 95th percentile of the distribution was 12.5 days33 |
| Range, d | 2–14 | 2–13 | 2–14 |
| Time from illness onset until hospitalization | 2–8 days | 0–16 days | 12.5 days (mean) (95% CI, 10.3–14.8), onset before Jan. 1 9.1 days (mean); 95% CI, 8.6–9.7 (onset Jan. 1–11)33 |
| Basic reproduction number (R0)b | 2–3 | <1 | 2.2 (95% CI, 1.4–3.9)33 |
| Patient characteristics | |||
| Adults | 93% | 98% | Nearly all reported patients are adults |
| Children | 5–7% | 2% | Children have been infrequently reported (<1% of cases)39 |
| Age range, y | 1–91 | 1–94 | 10–89 y |
| Average age, y | Mean, 39.9 | Median, 50 | 59 years (median)33 |
| Sex ratio (M:F) | 43%:57% | 64.5%:35.5% | 56%:44%33 |
| Mortality | |||
| Case fatality rate overall | 9.6% | 35–40% | Initial estimate is 1%38 |
| Clinical manifestations | From hospitalized patients32,36,37 | ||
| Fever | 99–100% | 98% | 83–100% |
| Cough | 62–100% | 83% | 59–82% |
| Myalgia | 45–61% | 32% | 11–35% |
| Headache | 20–56% | 11% | 7–8% |
| Diarrhea | 20–25% | 26% | 2–10% |
| Laboratory findings | |||
| Radiographic abnormalities on chest imaging | 94–100% | 90–100% | 100% |
| Leukopenia | 25–35% | 14% | 9–25% |
| Lymphopenia | 65–85% | 32% | 35–70% |
| Thrombocytopenia | 40–45% | 36% | 5–12% |
COVID-19, coronavirus disease 2019; MERS, Middle East respiratory syndrome; MERS-CoV, Middle East respiratory syndrome coronavirus; SARS, severe acute respiratory syndrome; SARS-CoV, severe acute respiratory syndrome coronavirus; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
Rasmussen. 2019 novel coronavirus and pregnancy. Am J Obstet Gynecol 2020.
a
Modified from Rasmussen et al23
b
Basic reproduction number, defined as average number of people who will become infected from a single infected person.