Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Jul;26(7):948.e1-948.e3.
doi: 10.1016/j.cmi.2020.04.040. Epub 2020 May 1.

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

G-U Kim  1 , M-J Kim  2 , S H Ra  2 , J Lee  2 , S Bae  2 , J Jung  2 , S-H Kim  3
Affiliations

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

G-U Kim et al. Clin Microbiol Infect. 2020 Jul.

Abstract

Objectives: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Keywords: Asymptom; COVID-19; Hyposmia; SARS-CoV-2; Symptoms.

PubMed Disclaimer

References

    1. Korean Society of Infectious Diseases Report on the epidemiological features of coronavirus disease 2019 (COVID-19) outbreak in the Republic of Korea from January 19 to March 2, 2020. J Korean Med Sci. 2010;35:e112. - PMC - PubMed
    1. https://blog.naver.com/daegu_news/221835400627 [Korean, Daegu city home page]
    1. Kim S.W., Lee K.S., Kim K., Lee J.J., Kim J.Y. A Brief Telephone Severity Scoring System and Therapeutic Living Centers Solved Acute Hospital-Bed Shortage during the COVID-19 Outbreak in Daegu, Korea. J Korean Med Sci. 2020;35:e152. - PMC - PubMed
    1. Chan J.F.W., Yuan S., Kok K.H., Huang L. A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster. Lancet. 2020;395:514–523. - PMC - PubMed
    1. Rothe C., Schunk M., Sothmann P., Bretzel G., Groeschl G., Wallrauch C. Transmission of 2019-nCoV infection from an asymptomatic contact in Germany. N Engl J Med. 2020;382:970–971. - PMC - PubMed