Coronavirus SARS-CoV2 infection (COVID-19)

Essential Evidence

Last Updated on 2022-01-07 © 2022 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 Since preprint servers have not been peer-reviewed, and the data and conclusions may change, information from them should be used with great caution if at all.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
  • • The most appropriate diagnostic test is RT-PCR of multiple specimens carried out according to guidelines. 9 Point-of-care PCR is highly specific, but sensitivity varies by manufacturer; rapid antigen testing has much lower sensitivity (56.2%) and should only be used in symptomatic patients with higher viral loads. 188B
  • Preventive measures include hand washing, surface cleaning, face masks, case isolation, quarantine of contacts for 14 days, school and university closures, social distancing, and sheltering at home. The most effective available face mask should be used when in indoor public spaces to prevent spread. Modeling indicates that only by doing all of these measures can the number of severe cases requiring ventilation not overwhelm hospitals. B
  • Two mRNA vaccines from Pfizer/BioNTech and Moderna have approximately 95% efficacy at preventing symptomatic disease and good safety against SARS-CoV-2. The adenovirus vectored vaccine from Johnson and Johnson/Janssen is 67% effective overall, but 74.4% in the US population that was studied. Vaccine effectiveness for the delta variant is about 87% to 90% overall, but lower among the immunocompromised and elderly. Boosters increase protection about 10-fold and are recommended at least 6 months after the second dose of vaccine. B
  • In patients not requiring oxygen or only requiring low-flow oxygen, remdesivir shortens the duration of hospitalization (11 vs. 15 days) and may reduce mortality slightly. 108B
  • Systemic corticosteroids are 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 171B
  • Two studies have found that use of inhaled budesonide in outpatients with early disease results in a shorter duration of symptoms and possibly a lower risk of hospitalization, death, and the need for urgent visits.B
  • A single RCT enrolling 1497 high risk outpatients with symptomatic COVID-19 compared fluvoxamine with placebo and reported a reduced likelihood of hospitalization (11% vs. 16%, NNT = 20, 95% CI 12-61).B 281
  • The monoclonal antibody bamlanivimab and the combination of casirivimab and imdevimab (Regeneron) have been given emergency use authorization for treatment of outpatients not on supplemental oxygen but at high risk for severe disease. A systematic review found an NNT of 21 to 24 to prevent hospitalization. 280B
  • In newly hospitalized patients not requiring mechanical ventilation, the Janus kinase inhibitor tofacitinib 10 mg twice daily reduced the composite of death or respiratory failure (18.1% vs. 29.0%, p = 0.04, NNT = 9). 265B
  • Multiple randomized controlled trials have confirmed that hydroxychloroquine (HCQ) 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
  • 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.Data support that after 10 days, the likelihood of transmission appears negligible. C
  • The overall case fatality rate is estimated to be between 0.5% and 0.9% and is higher in older patients and those with comorbidities. This estimate, from early in the pandemic, is likely lower now due to better treatment and ventilator management. 198 65B

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