A group of more than 220 children's hospitals is imploring the Biden administration for help, as a surge of young COVID-19 patients puts an "unprecedented strain" on their facilities and staff across the country.

Pediatric hospitals are "at or near capacity" and they expect to see more child patients as the school year resumes, according to the Children's Hospital Association.

"[T]here may not be sufficient bed capacity or expert staff to care for children and families in need," wrote association CEO Mark Wietecha in a letter to President Biden on Aug. 26.

"Our children's health care safety net is under unprecedented strain," Wietecha said in a news release. "Children's hospitals and their dedicated staffs are doing their part, and we hope every American, the White House and Congress can help."

There are a number of reasons for the pressure on the pediatric health care system.

The recent surge in COVID-19 cases driven by the delta variant has afflicted children more seriously than previous strains had, and children under age 12 still cannot get vaccinated. Some children are coming down with the coronavirus and RSV, a seasonal respiratory virus that can be dangerous in kids, at the same time.

Wietecha said hospitals are also seeing more children with serious mental and behavioral health issues, in part because of the social isolation they experienced last year and the general devastation wrought by the pandemic.

On top of that, he said, many children's hospitals are facing financial trouble because they admitted fewer patients during the widespread lockdowns early in the pandemic.

"All of these factors are converging and unfortunately setting up the perfect storm threatening national pediatric hospital capacity," Wietecha wrote.

Copyright 2021 NPR. To see more, visit https://www.npr.org.