The Centers for Disease Control and Prevention (CDC) has published data regarding coronavirus disease 2019 (COVID-19) cases in children aged 5 to 17. The purpose of this study, published in Morbidity and Mortality Weekly Report, is to provide information that might inform decisions about in-person learning and the timing and scaling of community mitigation measures.
The CDC indicated that between May and September 2020, the average weekly incidence of COVID-19 was significantly higher in adolescents aged 12 to 17 years (34.7 cases per 100,000 children) compared with children aged 5 to 11 years (19.0 cases per 100,000 children).
A research team identified confirmed cases of COVID-19 through individual case reports submitted by state health departments from March 1 to September 13, 2020. This case data was used to observe how demographic differences and underlying conditions affected rates of hospitalization, ICU admission, and death. Researchers analyzed trends by calculating a 7-day moving average, aggregated by week.
Researchers identified a total of 277,285 laboratory-confirmed cases of COVID-19 between March 1 and September 19, 2020; 101,503 (37%) cases were of children aged 5 to 11 years, and 175,782 (63%) were adolescents aged 12 to 17 years. Slightly more cases were identified in females (50.8%), and, among the 161,387 (58%) with COVID-19 who had complete information on race and ethnicity, 42% were Hispanic, 32% were White, and 17% were Black.
The weekly incidence of COVID-19 among school-aged children peaked the week of July 19 at 37.9 cases per 100,000 children (aged 5 to 11 years, 25.7; aged 12 to 17 years, 51.9). Weekly incidence then plateaued at an average of 34 cases per 100,000 from July 26 to August 23, 2020, then decreased to 22.6 cases per 100,000 the week of September 6, then increased to 26.3 per 100,000 for the final week of the study. The CDC study does not include information for the month of October, nor does the report cover college-age students.
To better understand trends in laboratory testing volume and percentage of positive test results, researchers used electronic laboratory data submitted by health departments from 37 states between May 31 and September 13, 2020.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing volume for school-aged children increased from 100,081 tests the week of May 31 to 322,227 during the week of July 12, then decreased to approximately 260,000 during August before increasing again in September. Researchers noted that test volume was higher among the adolescent cohort than the child cohort.
Only 5% of school-aged children with laboratory-confirmed COVID-19 were asymptomatic; 58% reported at least 1 symptom, and information on symptoms was missing or unknown for 37%. A total of 3240 (1.2%) of the children with COVID-19 were hospitalized; 404 (0.1%) required intensive care unit (ICU) admission, and 51 (<0.01%) died of COVID-19. Among hospitalized children with complete information on race and ethnicity (n=2473), 45% were Hispanic, 24% were Black, and 22% were White. Among children in the ICU with complete race and ethnicity data (n=321), 43% were Hispanic, 28% were Black, and 17% were White.
A total of 7738 children (approximately 3% of adolescents and 2% of younger children) with laboratory-confirmed COVID-19 reported having at least 1 underlying condition. Sixteen percent of school-aged children who were hospitalized, 27% of children who were admitted to an ICU, and 28% of children who died had at least 1 underlying condition.
The most commonly reported underlying condition was chronic lung disease, including asthma (55%), followed by disabilities including neurologic or neurodevelopmental disorders, intellectual or physical disability or vision or hearing impairment (9%), immunosuppressive diseases (7%), diabetes (6%), psychological conditions (6%), cardiovascular disease (5%), and severe obesity (4%).
“It is important for schools and communities to monitor multiple indicators of COVID-19 among school-aged children and layer prevention strategies to reduce COVID-19 disease risk for students, teachers, school staff, and families. These results can provide a baseline for monitoring trends and evaluating mitigation strategies,” researchers concluded.
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Leeb RT, Price S, Sliwa S, et al. COVID-19 trends among school-aged children — United States, March 1–September 19, 2020. MMWR Morb Mortal Wkly Rep. 2020;69(39):1410–1415.