Comparison of Symptoms and RNA Levels in Children and Adults With SARS-CoV-2 Infection in the Community Setting.

Importance The association between COVID-19 symptoms and SARS-CoV-2 viral levels in children living in the community is not well understood. Objective To characterize symptoms of pediatric COVID-19 in the community and analyze the association between symptoms and SARS-CoV-2 RNA levels, as approximated by cycle threshold (Ct) values, in children and adults. Design, Setting, and Participants This cross-sectional study used a respiratory virus surveillance platform in persons of all ages to detect community COVID-19 cases from March 23 to November 9, 2020. A population-based convenience sample of children younger than 18 years and adults in King County, Washington, who enrolled online for home self-collection of upper respiratory samples for SARS-CoV-2 testing were included. Exposures Detection of SARS-CoV-2 RNA by reverse transcription–polymerase chain reaction (RT-PCR) from participant-collected samples. Main Outcomes and Measures RT-PCR–confirmed SARS-CoV-2 infection, with Ct values stratified by age and symptoms. Results Among 555 SARS-CoV-2–positive participants (mean [SD] age, 33.7 [20.1] years; 320 were female [57.7%]), 47 of 123 children (38.2%) were asymptomatic compared with 31 of 432 adults (7.2%). When symptomatic, fewer symptoms were reported in children compared with adults (mean [SD], 1.6 [2.0] vs 4.5 [3.1]). Symptomatic individuals had lower Ct values (which corresponded to higher viral RNA levels) than asymptomatic individuals (adjusted estimate for children, −3.0; 95% CI, −5.5 to −0.6;P = .02; adjusted estimate for adults, −2.9; 95% CI, −5.2 to −0.6;P = .01). The difference in mean Ct values was neither statistically significant between symptomatic children and symptomatic adults (adjusted estimate, −0.7; 95% CI, −2.2 to 0.9;P = .41) nor between asymptomatic children and asymptomatic adults (adjusted estimate, −0.6; 95% CI, −4.0 to 2.8;P = .74). Conclusions and Relevance In this community-based cross-sectional study, SARS-CoV-2 RNA levels, as determined by Ct values, were significantly higher in symptomatic individuals than in asymptomatic individuals and no significant age-related differences were found. Further research is needed to understand the role of SARS-CoV-2 RNA levels and viral transmission.