Abstract
We aim to systematically review the characteristics of asymptomatic infection in the coronavirus disease 2019 (COVID-19). PubMed and EMBASE were electronically searched to identify original studies containing the rate of asymptomatic infection in COVID-19 patients before 20 May 2020. Then mate-analysis was conducted using R version 3.6.2. A total of 50 155 patients from 41 studies with confirmed COVID-19 were included. The pooled percentage of asymptomatic infection is 15.6% (95% CI, 10.1%-23.0%). Ten included studies contain the number of presymptomatic patients, who were asymptomatic at screening point and developed symptoms during follow-up. The pooled percentage of presymptomatic infection among 180 initially asymptomatic patients is 48.9% (95% CI, 31.6%-66.2%). The pooled proportion of asymptomatic infection among 1152 COVID-19 children from 11 studies is 27.7% (95% CI, 16.4%-42.7%), which is much higher than patients from all aged groups. Abnormal CT features are common in asymptomatic COVID-19 infection. For 36 patients from 4 studies that CT results were available, 15 (41.7%) patients had bilateral involvement and 14 (38.9%) had unilateral involvement in CT results. Reduced white blood cell count, increased lactate dehydrogenase, and increased C-reactive protein were also recorded. About 15.6% of confirmed COVID-19 patients are asymptomatic. Nearly half of the patients with no symptoms at detection time will develop symptoms later. Children are likely to have a higher proportion of asymptomatic infection than adults. Asymptomatic COVID-19 patients could have abnormal laboratory and radiational manifestations, which can be used as screening strategies to identify asymptomatic infection.
Keywords: COVID-19; Coronavirus disease 2019; SARS-CoV-2; asymptomatic infection; children coronavirus disease 2019; presymptomatic infection.
【저자키워드】 COVID-19, SARS-CoV-2, Coronavirus disease 2019, asymptomatic infection, presymptomatic infection, children coronavirus disease 2019, 【초록키워드】 coronavirus disease, Coronavirus disease 2019, coronavirus, children, Infection, C-reactive protein, Symptom, lactate dehydrogenase, Laboratory, Adults, Characteristics, Asymptomatic, White blood cell, COVID-19 infection, Patient, asymptomatic infection, Manifestations, presymptomatic, Follow-up, disease, patients, Lactate, COVID-19 patient, Asymptomatic COVID-19, blood cell, no symptoms, no symptom, 95% CI, confirmed COVID-19 patients, screening strategy, feature, identify, develop, proportion, the patient, conducted, can be used, searched, groups, much higher, recorded, initially asymptomatic patient, 【제목키워드】 Meta-analysis, coronavirus, systematic review,