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Laboratory-confirmed COVID-19 in children and youth in Canada, January 15-April 27, 2020

Our take —

Among cases of COVID-19 in children and youth reported to the Public Health Agency of Canada with available data, 11% were asymptomatic and 2% were hospitalized. In line with findings from other settings, a large proportion of cases were asymptomatic, though hospitalizations did still occur. These findings are limited in that many known cases did not have available data, and the cases that were included likely represent primarily symptomatic or high-risk individuals, likely leading to an underestimation of asymptomatic infections.

Study design

Other

Study population and setting

Laboratory-confirmed cases, reported to the Public Health Agency of Canada between January 15 and April 27, 2020, that had information on age were included in these analyses (n=24,079). The epidemiology of SARS-CoV-2 among children and youth, including the distribution of cases by gender and geography, and the proportion symptomatic and requiring hospitalization, was described. Children and youth were defined as those younger than 20 years. Data on whether cases were symptomatic or asymptomatic were available for about 25% of the included cases (5,939/24,079), and data on hospitalization were available for 57% of the sample (13,723/24,079).

Summary of Main Findings

Among the included cases, approximately 4% (n=938) were children or youth. The positivity rate was lower among those <20 years old (11.9 per 100,000) compared with those 20-59 years old (72.4 per 100,000) and those >60 years old (113.6 per 100,000). The median age of cases among children and youth was 13 years, and about half were female. 10.7% of cases with available symptom history were asymptomatic among children and youth, compared with 2.4% among those aged 20-59 years, and 4.1% in those aged 60 years or older. About 2% (n=15) of children and youth with available data were hospitalized, compared with 10.4% in those 20-59 years old and 35.6% in those >60 years old. In those less than 20 years, 4 hospitalizations were among those younger than one, 2 among those 10-14 years, and 9 among those 15-19 years. There were no hospitalizations among those 1-9 years old, and no deaths were reported for any individuals younger than 20 years of age.

Study Strengths

This study uses surveillance data to bolster our understanding of SARS-CoV-2 among children and youth, and how it compares to disease in older individuals.

Limitations

Data for these analyses represent only about half of the reported cases during the time period, due to missing information on age, hospitalization and lab confirmation, leading to potential selection bias. To add to this, during this time period testing was focused primarily on symptomatic, high-risk individuals seeking out testing. This may lead to underestimates of the number of asymptomatic cases, as well as an overestimate of hospitalizations and/or severity of disease.

Value added

This study provides further information on the epidemiology of SARS-CoV-2 among children and youth, including that there appear to be fewer cases and less severe disease in this age group.

This review was posted on: 28 July 2020