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

Abstract

IMPORTANCEThe 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 RELEVANCEIn 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.

Trajectory of viral load in a prospective population-based cohort with incident SARS-CoV-2 G614 infection

“…The higher average viral load among persons who reported COVID-19 symptoms than in asymptomatic persons suggests that the copy number is predictive of clinical disease. Our results of higher viral load in symptomatic than asymptomatic persons agree with findings in a recent community-based evaluating RNA levels in self-collected nasal swabs from adults and children (n=550) in Washington State 54 and a small (n=31) prospective study among patients hospitalized in China 55. However, others did not find associations between viral load and disease severity 36,56,57 Emerging data indicate that SARS-CoV-2 viral load in respiratory samples is an important driver of SARS-CoV-2 transmission 58 ; therefore, an accurate viral load measurement is an important parameter to develop mathematical models of viral spread.…”

Infants Younger Than 6 Months Infected With SARS-CoV-2 Show the Highest Respiratory Viral Loads

“…First, there were no differences among age groups in the median Ct values for the internal control gene ( RPP30 ) or in the time between symptom onset and sample collection ( Table 1 ). Second, there have been studies on the possible association between symptomatic infection and higher viral loads, with contrasting findings [ 6–8 ]. In this regard, it should be emphasized that in our cohort the frequency of symptomatic patients was similar across all age groups ( Table 1 ).…”

The COVID-19 pandemic in children and young people during 2020-2021: Learning about clinical presentation, patterns of spread, viral load, diagnosis and treatment

“…It has been shown that both symptomatic and asymptomatic children can carry high quantities of life, replicating SARS-CoV-2, which can create a potential reservoir for SARS-CoV-2 transmission and evolution of genetic variants [ 82 ]. Unsurprisingly, studies based on the virological profiling of asymptomatic children suggested that they do have lower viral loads, as well as faster virus clearance, with no significant age-related differences [ 79 , 80 ]. Among the affected children, activated and senescent cells were higher in adults than in children, while regulatory cells were higher in children.…”