American Journal of Infectious Diseases and Microbiology
ISSN (Print): 2328-4056 ISSN (Online): 2328-4064 Website: http://www.sciepub.com/journal/ajidm Editor-in-chief: Maysaa El Sayed Zaki
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American Journal of Infectious Diseases and Microbiology. 2020, 8(3), 113-117
DOI: 10.12691/ajidm-8-3-4
Open AccessArticle

Asymptomatic Coronavirus Disease 2019 (COVID-19) Carriers: Are They Infectious?

Yen Shen Wong1, , Dzawani Muhamad2, Soon Hin How3, Mohamed Sapian Mohamed4, Nasrah Mohd Arif2, Tze Vee Soh2, Suzana Mohd Hashim4 and Norazmi Abdullah5

1Department of Internal Medicine, Pekan Hospital, Pahang, Malaysia

2Infectious Disease Unit, Department of Internal Medicine, Tengku Ampuan Afzan Hospital, Pahang, Malaysia

3Respiratory Medicine Unit, Department of Internal Medicine, International Islamic University Malaysia, Pahang, Malaysia

4State Health Department of Pahang, Malaysia

5Hospital Director, Tengku Ampuan Afzan Hospital, Pahang, Malaysia

Pub. Date: September 10, 2020

Cite this paper:
Yen Shen Wong, Dzawani Muhamad, Soon Hin How, Mohamed Sapian Mohamed, Nasrah Mohd Arif, Tze Vee Soh, Suzana Mohd Hashim and Norazmi Abdullah. Asymptomatic Coronavirus Disease 2019 (COVID-19) Carriers: Are They Infectious?. American Journal of Infectious Diseases and Microbiology. 2020; 8(3):113-117. doi: 10.12691/ajidm-8-3-4

Abstract

Coronavirus disease 2019 (COVID-19) is highly contagious in symptomatic patients as it is thought to be transmitted through respiratory droplets. However, it is debatable whether asymptomatic COVID-19 patients are contagious due to lack of data. From 1st March to 15th April 2020, a total of 247 COVID-19 cases were admitted to Tengku Ampuan Afzan Hospital and 1010 close contacts were identified. We studied the epidemiological and clinical outcomes in asymptomatic subjects, as well as estimated the metrics of disease transmission between asymptomatic, symptomatic, and pneumonia subjects. From a total of 125 asymptomatic subjects, majority (n=116, 92.8%) remained asymptomatic upon discharge. Only 9 (7.2%) subjects developed mild symptoms after admission. Seven subjects had abnormal chest radiograph suggestive of pneumonia, and 22 subjects (17.6%) were found to have mild liver impairment. None of the asymptomatic subjects required oxygen support, inotropic support or ICU care during admission. Fifteen second generation COVID-19 cases were found transmitted from the asymptomatic group, with an attack rate of 3.9%, which was statistically significantly lower compared to the symptomatic (7.6%) or pneumonia groups (25.7%, p<0.001). In conclusion, asymptomatic COVID-19 patients show excellent clinical outcome. They are infectious but had a lower transmission risk compared with symptomatic or pneumonia patients.

Keywords:
Asymptomatic COVID-19 patients clinical outcome Coronavirus disease 2019 (COVID-19) Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Transmission risk

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