Skip to main content

Symptomatic Infection is Associated with Prolonged Duration of Viral Shedding in Mild Coronavirus Disease 2019: A Retrospective Study of 110 Children in Wuhan

Our take —

Among 110 children hospitalized with SARS-CoV-2 in Wuhan, China, this study found that asymptomatic infection was associated with shorter duration of viral shedding. Being younger than six years was associated with symptomatic infection, after adjusting for other factors. There are some concerns about representativeness of the asymptomatic patients, and how duration of viral shedding was classified among them.

Study design

Retrospective Cohort

Study population and setting

A total of 110 children who tested positive for SARS-CoV-2 infection and were hospitalized with mild or asymptomatic disease at Wuhan Children’s Hospital between January 30 and March 10, 2020 were included in this retrospective study. Asymptomatic patients came to the hospital either because they had been exposed or had abnormal chest imaging. Information on demographics, clinical and laboratory characteristics, radiology and therapeutics were extracted from electronic medical records. Duration of viral shedding was measured from illness onset (or date of last exposure or abnormal chest image in asymptomatic patients) to discharge, and was compared by whether or not patients were symptomatic. Factors associated with duration of viral shedding were explored, along with factors associated with symptomatic infection.

Summary of Main Findings

Among the 110 children included in this study, 74% (n=81) were symptomatic and 26% (n=29) were asymptomatic. Duration of viral shedding was shown to be longer in symptomatic patients (median 17 days) compared with asymptomatic patients (median 11 days). Factors associated with longer duration of viral shedding using Kaplan-Meier analyses included symptomatic infection, fever, pneumonia, and lower lymphocyte counts. Younger age, that is less than six years old, was associated with symptomatic infection after adjustment for other possible predictors.

Study Strengths

The strength of this study is the availability of data on both asymptomatic and symptomatic children from the same patient population.


All individuals included in this study were hospitalized, and there is some concern about whether or not these asymptomatic patients represent all asymptomatic patients. Additionally, duration of viral shedding was defined differently among those asymptomatic patients (i.e. time from last exposure or time from abnormal chest image for asymptomatic patients versus time from symptoms onset among symptomatic patients), which would likely cause an underestimation of the difference in viral shedding periods since the incubation period from exposure to symptom onset was not included in the symptomatic patients. The breakdown of these asymptomatic patients is not presented, and these differences may have an impact on the duration of viral shedding. Finally, the factors found to be associated with viral shedding are only examined in univariate analyses. It is unclear why adjustment for confounders was not considered.

Value added

There are limited epidemiologic data on SARS-CoV-2 infection among both children and asymptomatic patients. This study examines both duration of viral shedding comparing symptomatic with asymptomatic patients, and the role of younger age on symptomatic infection.

This review was posted on: 10 June 2020