Clinical Characteristics and Viral RNA Detection in Children With Coronavirus Disease 2019 in the Republic of Korea

Abstract

Importance: There is limited information describing the full spectrum of coronavirus disease 2019 (COVID-19) and the duration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA detection in children.

Objective: To analyze the full clinical course and the duration of SARS-CoV-2 RNA detectability in children confirmed with COVID-19 in the Republic of Korea, where rigorous public health interventions have been implemented.

Design, setting, and participants: This case series of children with COVID-19 was conducted in 20 hospitals and 2 nonhospital isolation facilities across the country from February 18, 2020, to March 31, 2020. Children younger than 19 years who had COVID-19 were included.

Exposures: Confirmed COVID-19, detected via SARS-CoV-2 RNA in a combined nasopharyngeal and oropharyngeal swab or sputum by real-time reverse transcription-polymerase chain reaction.

Main outcomes and measures: Clinical manifestations during the observation period, including the time and duration of symptom occurrence. The duration of SARS-CoV-2 RNA detection was also analyzed.

Results: A total of 91 children with COVID-19 were included (median [range] age, 11 [0-18] years; 53 boys [58%]). Twenty children (22%) were asymptomatic during the entire observation period. Among 71 symptomatic cases, 47 children (66%) had unrecognized symptoms before diagnosis, 18 (25%) developed symptoms after diagnosis, and only 6 (9%) were diagnosed at the time of symptom onset. Twenty-two children (24%) had lower respiratory tract infections. The mean (SD) duration of the presence of SARS-CoV-2 RNA in upper respiratory samples was 17.6 (6.7) days. Virus RNA was detected for a mean (SD) of 14.1 (7.7) days in asymptomatic individuals. There was no difference in the duration of virus RNA detection between children with upper respiratory tract infections and lower respiratory tract infections (mean [SD], 18.7 [5.8] days vs 19.9 [5.6] days; P = .54). Fourteen children (15%) were treated with lopinavir-ritonavir and/or hydroxychloroquine. All recovered, without any fatal cases.

Conclusions and relevance: In this case series study, inapparent infections in children may have been associated with silent COVID-19 transmission in the community. Heightened surveillance using laboratory screening will allow detection in children with unrecognized SARS-CoV-2 infection.

Figure 1.. Epidemic Curve of Children With Coronavirus Disease 2019 in Korea From February 14 to March 31, 2020

Other contacts indicates close contact with a kindergarten teacher, care helper at a rehabilitation center, or with other individual with a confirmed case without a social relationship.

Figure 2.. Time Course From Time of Diagnosis to End of Isolation in Children With Coronavirus Disease 2019

Time courses are presented according to the spectrum of symptom occurrence. Health care isolation was lifted when patients had improved symptoms and 2 consecutive negative polymerase chain reaction results from nasopharyngeal and oropharyngeal swab specimens collected at least 24 hours apart. The dark colors indicate the symptomatic period, and the light colors indicate the asymptomatic period. The gray dots indicate the date of release from isolation.

Figure 3.. Duration From Symptom Onset to Negative Test Results and End of Isolation

A, The mean duration from symptom onset to negative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) results of the asymptomatic group and the groups with upper respiratory tract infection (URTIs) and lower respiratory tract infection (LRTIs). The line indicates the mean value. B, Kaplan-Meier curve for time to end of isolation. Health care isolation was lifted when patients had improved symptoms and 2 consecutive negative polymerase chain reaction results from nasopharyngeal and oropharyngeal swab specimens collected at least 24 hours apart. For asymptomatic cases, the number of days from diagnosis, instead of days from symptom onset, was applied.