The U.S. reported more than 97,000 child COVID-19 cases from July 16 to July 30, a 40-percent increase, according to a new report, published by the American Academy of Pediatrics and the Children's Hospital Association, based on publicly reported data from 49 states by the end of July. 

The age range for children varied by state, with most states defining children as those up to age of 19 and one state - Alabama - pushing the limit to 24. 

Cumulatively, 338,982 U.S. children tested positive for the coronavirus, accounting for 8.8 percent of the total confirmed cases in the country. That means 447 per 100,000 children were infected by the virus, the report showed.  

At least 86 children have died since May. Last week, a 7-year-old boy with no pre-existing conditions became the youngest coronavirus victim in Georgia. 

The report comes during back-to-school season, as health officials are trying to figure out how the virus affects children and how it's spread among young people. Some schools have begun welcoming crowds back to class and others have had to readjust their reopening plan. 

Some U.S. leaders - including President Donald Trump - have said the virus doesn't pose a large risk to children. In July, Trump has urged schools to reopen even as coronavirus cases spiked. 

But one recent study suggests teenagers can transmit the virus just as much as adults. Another study said children younger than five carry a higher viral load than adults, raising even more questions about their role in transmission.