Important to consider age when assessing children for COVID-19 severity, study finds

Key takeaways:

• Pediatric ICU admission for COVID-19 decreased during the pandemic.
• However, ventilatory and oxygen support did not decrease among the youngest children.

A study of more than 30,000 hospitalized children with SARS-CoV-2 infection found that ICU admissions for COVID-19 decreased over the course of the pandemic but ventilatory and oxygen support for the youngest children did not.

“These findings highlight the importance of considering different pediatric age groups when assessing disease severity in SARS-CoV-2,” the authors wrote.

The motivation behind the study was a desire to assess the impact of SARS-CoV-2 variants on the severity of COVID-19 in children, according to one of its authors.

“Since the emergence of the virus in late 2019, the global trajectory of the COVID-19 pandemic included periods dominated by the ancestral virus, followed by the alpha/beta/delta variant, and eventually the emergence of the omicron variant,” Yanshan Zhu, MMed, a PhD student at the University of Queensland, told Healio.

“However, although COVID-19 infections generally manifest as milder in children and infants, the spread of the omicron variant led to an unprecedented surge in pediatric cases and hospitalizations. The question of whether these dominant circulating SARS-CoV-2 variants of concern (VOC) are associated with differences in COVID-19 severity among hospitalized children, especially in terms of related age-specific patterns, remained unclear. Furthermore, it is difficult to determine if any of these differences are due to functional changes in the virus or reflect changes in the host through increased immunity or changes in health care.”

In a multicenter retrospective cohort study, Zhu and co-authors examined clinical data of 31,785 hospitalized pediatric patients in the United Kingdom, Portugal, Italy, Switzerland, South Africa, Brazil, the United States, Thailand and Australia between Jan. 1, 2020, and Mar. 31, 2022. They divided the data into three different time frames, categorized by the dominant strain or strains: T1 for the initial, “ancestral” SARS-CoV-2 virus; T2 for pre-omicron variants; and T3 for omicron.

“The primary outcomes of interest were the changes in severe disease outcomes across the different time frames dominated by different VOC and age groups,” Zhu said. “Specifically, we aimed to determine whether there were differences in ICU admission rates, ventilatory support, and oxygen therapy requirements among the pediatric patients.”
The data showed a reduction in risk ratios between the first and third time frames in ICU admission (RR = 0.39, 95% CI, 0.32-0.48), ventilatory support (RR = 0.37; 95% CI, 0.27-0.51) and oxygen therapy (RR = 0.47; 95% CI, 0.32-0.70) among children aged 5 to 18 years.

However, ventilatory and oxygen support did not decrease among children aged younger than 5 years, although there was a reduction in ICU admission (RR for children younger than 6 months = 0.56; 95% CI, 0.42-0.75; RR for age 6 months to younger than 5 years = 0.61, 95% CI; 0.47-0.79).

“What caught our attention was the unexpected observation that despite this decrease in ICU admissions, the need for ventilatory support and oxygen therapy did not consistently decline in this specific age group,” Zhu said. “It suggested that while ICU admissions were decreasing, the requirements for respiratory support remained relatively stable in the youngest children.”

Conversely, Zhu said the reduction in ICU admissions, ventilatory support and oxygen therapy for children aged 5 to younger than 18 years across the different waves aligned more closely with their expectations.

“This decreasing need for medical interventions in this age group mirrored trends observed in adult populations during the evolution of SARS-CoV-2 variants,” Zhu said. “The contrasts in disease severity outcomes between the two age groups, especially the differing respiratory support needs, were less expected and opened avenues for potential mechanistic investigations.”

She reiterated that the findings highlight the importance of considering different pediatric age groups when assessing disease severity in COVID-19.

“Pediatricians should be particularly careful in monitoring respiratory support requirements for the youngest patients, even as overall ICU admissions decrease,” Zhu said. “Timely and appropriate interventions can be crucial in ensuring optimal outcomes for these children.”