Clinical characteristics of asymptomatic and symptomatic patients with mild COVID-19

• Published in: Clinical microbiology and infection Vol. 26; no. 7; pp. 948.e1 - 948.e3
• Main Authors: Kim, G.-u., Kim, M.-J., Ra, S.H., Lee, J., Bae, S., Jung, J., Kim, S.-H.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.07.2020; European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd
• Subjects: Asymptom; Asymptomatic Infections - epidemiology; Betacoronavirus; Communicable Disease Control - methods; Coronavirus Infections - diagnosis; Coronavirus Infections - epidemiology; COVID-19; Humans; Hyposmia; Olfaction Disorders - epidemiology; Pandemics; Pneumonia, Viral - diagnosis; Pneumonia, Viral - epidemiology; Prevalence; Republic of Korea - epidemiology; SARS-CoV-2; Symptoms; Republic of Korea; Asymptom; COVID-19; SARS-CoV-2; Hyposmia; Symptoms
• ISSN: 1198-743X; 1469-0691
• DOI: 10.1016/j.cmi.2020.04.040

Detailed knowledge on the prevalence of asymptomatic cases of coronavirus disease 2019 (COVID-19) and the clinical characteristics of mild COVID-19 is essential for effective control of the COVID-19 pandemic. We determined the prevalence of asymptomatic cases of COVID-19 and characterized the symptoms of patients with mild COVID-19. Study participants were recruited from a community facility designated for the isolation of patients without moderate-to-severe symptoms of COVID-19 in South Korea. The prevalence of asymptomatic patients at admission and the detailed symptoms of mild COVID-19 were evaluated through a questionnaire-based survey. Diagnosis of COVID-19 was confirmed by real-time RT-PCR. Of the 213 individuals with COVID-19, 41 (19.2%) were asymptomatic until admission. Among the remaining patients with mild COVID-19, the most common symptom was cough (40.1%; 69/172), followed by hyposmia (39.5%; 68/172) and sputum (39.5%; 68/172). Of the 68 individuals with hyposmia, 61 (90%) had accompanying symptoms such as hypogeusia, nasal congestion or rhinorrhoea. Fever (>37.5°C) was only observed in 20 (11.6%) individuals. As much as one-fifth of individuals with COVID-19 remained asymptomatic from exposure to admission. Hyposmia was quite frequent among individuals with mild COVID-19, but fever was not. Social distancing should be strongly implemented to prevent disease transmission from asymptomatic individuals or those with mild and inconspicuous symptoms.