Child Coronavirus Cases Spiked by 90 Percent. It's Likely Down to Two Key Reasons

Hundreds of thousands of children have been diagnosed with the coronavirus in the U.S. since the start of the pandemic, according to a report. Of those, almost 200,000 were reported in the four weeks following July 9, marking a 90 percent increase in child cases.

A total of 380,174 child COVID-19 cases were reported between the start of the pandemic and August 6, making up 9.1 percent of all cases, or 501 per 100,000 children in the U.S., according to the American Academy of Pediatrics and the Children's Hospital Association. The data came from 49 states, New York City, D.C., Puerto Rico, and Guam. Between July 9 and August 6, 179,990 new cases were reported.

According to Johns Hopkins University, the U.S. is leading the world in COVID-19 cases and deaths. Of the global total of over 20.2 million, the U.S. has more than 5.1 million diagnoses, with cases surging across the country.

More than 164,000 people have died in the U.S., out of the worldwide total of over 741,000. On Tuesday, 46,808 cases were reported in the country.

The authors of the report noted that the definition of a "child" varied by state, between 0 to 14 and 0 to 24 years old.

Mirroring the evidence that has accumulated since the start of the pandemic that children are more likely to have mild COVID-19, fatalities were relatively low, at 0 to 0.4 percent of all deaths, with 20 states reporting none. In those that did report deaths, 0 to 0.5 percent of cases resulted in death.

Why has there been a spike in cases?

The data from the report alone can't explain why there was a rise in cases in the four weeks following early July, according to experts who told Newsweek a number of factors may be at play.

Increased testing may play a part. Alvaro Moreira, assistant professor in the department of pediatrics at UT Health, San Antonio, pointed out that children must provide proof they are coronavirus-free before they can attend some summer camps and daycare centers.

Families may also be seeking tests as they could have heard in the news of a dangerous and life-threatening complication of COVID-19 known as multisystem inflammatory syndrome in children.

"We know that 20 percent of children will be asymptomatic so the test may be picking up these patients as well," he said.

Stephen Morse, professor of epidemiology at the Mailman School of Public Health, Columbia University, told Newsweek he believed most of the increase in July—"probably essentially all"—is due to children encountering the virus more.

Echoing Morse's take, Robert Carnahan, associate professor of pediatrics and radiology and radiologic sciences at Vanderbilt University Medical Center, told Newsweek the spike may have been the result of overall changes in behavior across all age groups.

In May, many restrictions to prevent the spread of the coronavirus in the U.S. were lifted and there was a lag of around four weeks for cases to rise, he said.

"As it [the spread of the virus] initially took off, people did not really take note so it continued. In July we saw many locations with burgeoning caseloads. At that point people took notice, but just like the uptick, leveling things off will involve a lag period."

He said: "I think in the last week or so, we are finally seeing some leveling off. But this will last only as long as we have some kind of compliance with control measures."

Carnahan said he has not seen any data to suggest the relative rate in kids increased as compared to adults.

Professor Andrew T. Pavia, chief in the division of pediatric infectious diseases at the University of Utah, told Newsweek: "Another factor is likely that as tests became more available, we loosened the criteria for testing. Children with mild illness, contact with known cases, and those undergoing surgery or going to summer camps were tested."

Asked whether the trend will continue, Moreira said: "[It's] hard to say, but I hope not. We are entering uncharted territories and we are learning and adapting as we try to return to 'normalcy'.

"However, I will iterate that evidence suggests that we can curtail this trend by social distancing, avoiding large gatherings, handwashing, and wearing a mask in public."

As schools weigh-up what to do in the fall, Moreira said the re-openings of some have demonstrated the infectivity of the virus. In one school district in Georgia, for example, more than 900 students and staff have been quarantined after 59 students tested positive after it re-opened on August 3, according to a statement from Cherokee Country School District.

"All it takes is one positive child/teacher to have a potentially hazardous outbreak," he said.

Kate Connor, assistant professor of pediatrics at Johns Hopkins University School of Medicine, told Newsweek: "This increase in pediatric cases underscores the fact that children do become infected with coronavirus and can become ill."