Fever and cough were more common among Canadian children infected with the SARS-CoV-2 Delta and Omicron variants than the original, wild-type virus and the Alpha variant, but rates of hospitalization and intensive care unit (ICU) admission stayed the same over time, finds a study published yesterday in JAMA Network Open.
The Pediatric Emergency Research Canada COVID Study Group assessed symptoms among 1,440 COVID-19 patients younger than 18 years seen at 14 Canadian emergency departments (EDs) from August 4, 2020, to February 22, 2022. Research assistants telephoned patients' caregivers a median of 2 days after their ED visit. Median age was 2.0 years.
Omicron patients most likely to be treated
Whole-genome sequencing was conducted for 26.9% of patients, identifying Alpha (40.7%), Delta (45.6%), and Omicron (11.9%), in addition to one Beta and six Gamma cases; the remainder of the tests were inconclusive.
Children with Alpha infections reported the fewest COVID-19 symptoms (195 of 237 [82.3%]), while Omicron patients reported the most (434 of 468 [92.7%]). Relative to the wild-type virus, Omicron and Delta were more strongly tied to fever (odds ratios [ORs], 2.00 and 1.93, respectively) and cough (ORs, 1.42 and 1.57).
Upper respiratory tract symptoms were most common with Delta (OR, 1.96), while lower respiratory tract and systemic symptoms were tied to Omicron (ORs, 1.42 and 1.77, respectively).
Compared with Delta patients, Omicron patients were more likely to undergo chest radiography (difference, 9.7%), receive intravenous fluids (difference, 5.6%) or corticosteroids (difference, 7.9%), and return to the ED (difference, 8.8%). The proportions of patients hospitalized or admitted to an ICU did not differ among variants.
The proportions of infected children experiencing undesirable outcomes in our study remained stable.
Patients with Delta infections were most often also infected with other respiratory viruses (40.0%). Of the 69.3% of parents asked about their child's COVID-19 vaccination status, 8.0% said they had received at least one dose, 81.8% were unvaccinated, and 10.2% were unsure.
"Although the characteristics of presenting symptoms changed as the SARS-CoV-2 virus evolved, unlike in adults where mortality declined in subsequent waves, the proportions of infected children experiencing undesirable outcomes in our study remained stable," the authors wrote.