SARS-CoV-2 Infections Among Children in the Biospecimens from Respiratory Virus-Exposed Kids (BRAVE Kids) Study

Abstract

Background: Children with SARS-CoV-2 infection typically have mild symptoms that do not require medical attention, leaving a gap in our understanding of the spectrum of illnesses that the virus causes in children.

Methods: We conducted a prospective cohort study of children and adolescents (<21 years of age) with a SARS-CoV-2-infected close contact. We collected nasopharyngeal or nasal swabs at enrollment and tested for SARS-CoV-2 using a real-time PCR assay.

Results: Of 382 children, 289 (76%) were SARS-CoV-2-infected. SARS-CoV-2-infected children were more likely to be Hispanic (p<0.0001), less likely to have a history of asthma (p=0.009), and more likely to have an infected sibling contact (p=0.0007) than uninfected children. Children ages 6-13 years were frequently asymptomatic (38%) and had respiratory symptoms less often than younger children (30% vs. 49%; p=0.008) or adolescents (30% vs. 59%; p<0.0001). Compared to children ages 6-13 years, adolescents more frequently reported influenza-like (61% vs. 39%; p=0.002), gastrointestinal (26% vs. 9%; p=0.003), and sensory symptoms (43% vs. 9%; p<0.0001), and had more prolonged illnesses [median (IQR) duration: 7 (4, 12) vs. 4 (3, 8) days; p=0.004]. Despite the age-related variability in symptoms, we found no differences in nasopharyngeal viral load by age or between symptomatic and asymptomatic children.

Conclusions: Hispanic ethnicity and an infected sibling close contact are associated with increased SARS-CoV-2 infection risk among children, while a history of asthma is associated with decreased risk. Age-related differences in the clinical manifestations of SARS-CoV-2 infection must be considered when evaluating children for COVID-19 and in developing screening strategies for schools and childcare settings.

Figure 1.. Flowchart of enrollment and determination of SARS-CoV-2 infection status in the study population

Figure 2.. Prevalence of reported symptom complexes in 289 SARS-CoV-2-infected children by age.

Age was categorized into three groups (0–5 years, 6–13 years, and 14–20 years), and the prevalence of specific symptom complexes are reported for children in each age group. Symptom complexes include respiratory symptoms (cough, difficulty breathing, nasal congestion, or rhinorrhea), influenza-like symptoms (headache, myalgias, or pharyngitis), gastrointestinal symptoms (abdominal pain, diarrhea, or vomiting), and sensory symptoms (anosmia or dysgeusia). Error bars correspond to the 95% confidence interval for each symptom complex in each age group.

Figure 3.. Evaluation of nasopharyngeal SARS-CoV-2 viral load among 178 SARS-CoV-2-infected children by age, symptoms, and timing of sample collection relative to symptom onset.

Panel A shows viral loads among SARS-CoV-2-infected children by age group; no difference in viral load was seen with respect to age (p=0.54). Panel B shows viral loads in symptomatic SARS-CoV-2-infected children relative to the timing of symptom onset (days −3 to 20). SARS-CoV-2 viral loads were highest in the 3 days before and after symptom onset [median (IQR): 6.6 (4.9, 7.8) log copies/mL] and declined with increasing time from symptom onset (p<0.0001). Adjusting for the timing of sample collection relative to symptom onset, there were no differences in nasopharyngeal viral load by age group (0–5 years vs. 14–20 years, p=0.10; 6–13 years vs. 14–20 years, p=0.53). Panel C shows viral loads among SARS-CoV-2-infected children who reported one or more symptoms and children who reported no symptoms; viral loads were similar among asymptomatic children and children with symptomatic COVID-19 [median (IQR): 3.7 (2.6, 6.5) vs. 4.1 (3.0, 5.4) log copies/mL; p=0.53].