72,000 COVID cases reported among US children, teens last week, a 'substantial' spike

With the new school year stirring concerns about protecting children from COVID-19, the American Academy of Pediatrics said Tuesday there's been a "substantial" increase in cases among children.

Nearly 72,000 children and teens caught Covid-19 last week -- five times as many as at the end of June, the group said.

The definition of a child varies by state, but generally includes those up to age 17 or 18.

Covid-19 protocols vary across the country, but when children go back to school, districts will need to know how to respond to outbreaks quickly.

Districts need to be prepared to enact contact tracing, testing, the quarantining of people who were exposed to the virus and the isolation of people with infections, Dr. William Schaffner, a professor at Vanderbilt University School of Medicine and medical director of the National Foundation for Infectious Diseases, told CNN.

While most schools follow those steps to isolate cases, contact trace and test, response plans can vary state by state and school district by school district, Kim Anderson, executive director of the National Education Association, told CNN.

"From what we understand, it does depend on what district you are in. The district should have very well thought-out outbreak plans that have included the voices of educators and parents and community members in the crafting of those plans, and they should have plans that follow the CDC recommendations," Anderson said.

"Our recommendation to all students and school districts is to follow the medical experts and follow the CDC," she said.