Comparison of clinical and epidemiological characteristics of asymptomatic and symptomatic SARS-CoV-2 infection: A multi-center study in Sichuan Province, China. Issue 37 (September 2020)

• Record Type: Journal Article
• Authors: Kong, Weifang; Wang, Yuting; Hu, Jinliang; Chughtai, Aamer; Pu, Hong
• Is Part Of: Travel medicine and infectious disease. Issue 37(2020)
• Publication Date: 2020-09
• Subjects: Coronavirus disease-19 -- SARS-CoV-2 -- Clinical characteristics -- Asymptomatic -- Epidemiology; SARS-CoV-2 severe acute respiratory syndrome coronavirus 2 -- COVID-19 Coronavirus disease-19 -- CT computerized tomography -- SD standard deviation; Travel -- Health aspects -- Periodicals; Communicable diseases -- Periodicals; Tropical medicine -- Periodicals; 610.5
• DOI: 10.1016/j.tmaid.2020.101754
• Languages: English
• ISSNs: 1477-8939

Abstract

Abstract: Objectives: Asymptomatic infection of SARS-CoV-2 has become a concern worldwide. This study aims to compare the epidemiology and the clinical characteristics of SARS-CoV-2 infection in asymptomatic and symptomatic individuals. Methods: A total of 511 confirmed SARS-CoV-2 infection cases, including 100 asymptomatic (by the time of the pathogenic tests) and 411 symptomatic individuals were consecutively enrolled from January 25 to February 20, 2020 from hospitals in 21 cities and 47 counties or districts in Sichuan Province. Epidemiological and clinical characteristics were compared. Results: Compared to the symptomatic patients, the asymptomatic cases were younger (P < 0.001), had similar co-morbidity percentages (P = 0.609), and came from higher altitude areas with lower population mobility (P < 0.001) with better defined epidemiological history (P < 0.001). 27.4% of well-documented asymptomatic cases developed delayed symptoms after the pathogenic diagnosis. 60% of asymptomatic cases demonstrated findings of pneumonia on the initial chest CT, including well-recognized features of coronavirus disease-19. None of the asymptomatic individuals died. Two elderly individuals with initially asymptomatic infection developed severe symptoms during hospitalization. One case of possible virus transmission by a patient during the incubation period was highly suspected. Conclusions: The epidemiological and clinical findings highlight the significance of asymptomatic infection with SARS-CoV-2. Inspecting the epidemiological history would facilitate the identification of asymptomatic cases. Evidence supports the chest CT scans for confirmed asymptomatic cases to evaluate the extent of lung involvement. Highlights: The asymptomatic cases were younger, with better defined epidemiological history. 60% of asymptomatic cases showed positive findings of pneumonia on the initial CT. At least one case of possible transmission during incubation period was suspected.