(NewsNation) — The U.S. Centers for Disease Control and Prevention (CDC) reports flu activity remains “elevated across the country,” with “high” or “very high” respiratory virus activity in more than half of the states, in a press release Friday.

The update follows Tuesday’s report that flu hospitalizations have reached a decadelong high in the U.S. and call-outs by The American Academy of Pediatrics (AAP) and the Children’s Hospital Association (CHA).

The two institutions wrote a joint letter to President Biden and Health and Human Services Secretary Xavier Becerra on Monday, Nov. 15, asking the Biden administration to declare an emergency to support a national response to an “alarming surge of pediatric respiratory illnesses, including respiratory syncytial virus (RSV) and influenza.” 

According to the CDC, RSV is a “common respiratory virus that usually causes mild, cold-like symptoms.”

The letter also mentions that pediatric hospitals were experiencing capacity issues that only emergency assistance from the White House can alleviate.

“President Biden and Secretary Becerra have been invaluable leaders to children’s hospitals across the country during the COVID-19 pandemic, and we implore them to renew their commitment to pediatric health care and give us the resources necessary to control the ongoing RSV and flu surge with the continuing children’s mental health emergency,” said CHA CEO Mark Wietecha. “Our system is stretched to its limit and without immediate attention the crisis will only worsen.”

The joint letter was published the same day the California Department of Public Health reported the first death of a child under the age of 5 from RSV this winter season.

While the majority of people recover within two weeks, RSV can be fatal, as it has claimed the lives of 1,300 people, including at least four children, so far this season.

Dr. Deborah Birx, the former White House COVID-19 response coordinator under President Donald Trump, advises everyone to get tested if they’re experiencing any type of respiratory complications.

“We should be telling every American all these respiratory diseases look alike,” Brix said. “The only way you can tell the difference is to get a laboratory test. Any respiratory symptoms, get a test; get tested.”