Coronavirus SARS-CoV2 infection (COVID-19)

Essential Evidence

Last Updated on 2020-09-28 © 2020 John Wiley & Sons, Inc.

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Mark H. Ebell, MD, MS, Professor, College of Public Health, University of Georgia
Mindy A. Smith, MD, MS, Clinical Professor, Department of Family Medicine, Michigan State University
Henry C. Barry, MD, MD, MS, Professor Emeritus, Michigan State University
Pete Yunyongying, MD, FACP, Associate Professor , Carle-Illinois College of Medicine, University of Illinois
John Hickner MD, MS, Professor Emeritus, University of Illinois-Chicago

Mark H. Ebell, MD, MS, Professor, College of Public Health, University of Georgia

Overall Bottom Line

  • EDITOR'S NOTE: This topic has been made freely available and is being updated regularly. We are at times linking to preprint servers and providing direct links to articles where possible, and most of this literature has been made freely available. As preprint work becomes peer reviewed and formally published, we will update the citations. Since preprint servers have not been peer-reviewed, and the data and conclusions may change, information from them should be used with great caution if at all.
  • Suspect COVID-19 when the virus is circulating in the population and a patient reports signs and symptoms of respiratory tract infection, or less commonly fever and neurologic symptoms or thrombosis. Most common symptoms are fever, cough, myalgias, and dyspnea; loss of taste and smell are also common. Approximately 40% of all patients are asymptomatic but appear to be as infectious as symptomatic patients. B
  • Preventive measures include hand washing, surface cleaning, case isolation, quarantine of contacts for 14 days, school and university closures, and general social distancing/sheltering at home. Modeling indicates that only by doing all of these measures can the number of severe cases requiring ventilation not overwhelm hospitals.B
  • Mask and isolate patients on presentation to a healthcare facility and obtain PCR from nasopharynx and oropharynx. Also test for influenza and strep throat if clinically suspected. C
  • The combination of age and CRP can be used to identify patients at low, moderate and high risk of severe illness (see Prognosis section below).B
  • Patients can be considered cured using a test-based strategy (recovery from fever without antipyretics and without respiratory symptoms plus 2 negative PCR tests 24 hours apart). For outpatients in settings where tests are not widely available, the CDC recommends that isolation be maintained for at least 10 days after illness onset and at least 3 days (72 hours) after recovery, defined as: at least 3 days free of fever without antipyretics, 3 days without respiratory symptoms, and at least 7 days after onset of symptoms. C
  • Treatment is primarily supportive and includes monitoring oxygen saturation.
  • Remdesivir shortens the duration of hospitalization (11 vs. 15 days) and may reduce mortality slightly. 108B
  • Corticosteroids have been shown in a large UK trial with 6425 patients to be highly effective at reducing mortality in patients with COVID-19 who are mechanically ventilated (NNT = 7) or who are on oxygen (NNT = 20) but not in hospitalized patients not requiring oxygen. 161 Their use also decreases the likelihood of requiring mechanical ventilation. 171B
  • Multiple randomized controlled trials have confirmed that hydroxychloroquine is not effective for severe disease, mild disease, early disease, or as post-exposure prophylaxis, and is associated with a higher risk of adverse events. 173 105A
  • The overall infection fatality rate is estimated to be 0.5% to 0.9% and is higher in older patients and those with comorbidities. 65 As of September 24th, the Johns Hopkins Center for Health Security reports that there have been 984,813 deaths and 32,356,829 confirmed cases worldwide, 203,147 deaths and 6,997,468 confirmed cases in the US (2.9% case fatality ratio), 9,304 deaths and 151,982 confirmed cases in Canada (6.1% case fatality ratio), and 42,025 deaths and 425,765 confirmed cases in the UK (9.9% case fatality ratio). Mortality rates per 100,000 are 62.0 in the US, 25.1 in Canada, and 63.2 in the UK. These rates are higher than the true case and infected fatality rates due to the large number of undiagnosed mild and asymptomatic cases. B

EBMG Audio

Recovery from pneumonia

Acute stage of pneumonia


Table 1: Frequency of symptoms and laboratory findings among patients with confirmed COVID-19 based on a systematic review of 43 studies in 3600 Chinese patients.

Clinical FindingFrequency (95% CI)
Signs and symptoms
Fever83% (78 - 88)
Cough60% (54 - 66)
Fatigue38% (30 - 46)
Myalgia28% (21 - 36)
Dyspnea25% (17 - 34)
Diarrhea8.4% (4.8 - 13)
Laboratory tests
C-reactive protein elevated69% (58 - 78)
Lactage dehydrogenase (LDH) elevated52% (31 - 72)
D-dimer elevated29% (4.8 - 62)
Imaging findings
Ground glass opacity80% (67 - 90)
Bilateral pneumonia73% (63 - 82)
Unilateral pneumonia25% (12 - 41)