We compared symptoms and characteristics of 4961 ambulatory patients with and without laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection. Findings indicate that clinical symptoms alone would be insufficient to distinguish between coronavirus disease 2019 and other respiratory infections (eg, influenza) and/or to evaluate the effects of preventive interventions (eg, vaccinations).
Keywords: COVID-19; case definitions; influenza; observational research studies; vaccine effectiveness.
Published by Oxford University Press on behalf of Infectious Diseases Society of America 2020.