Please Note

The Washington Post is providing this important information about the coronavirus for free. For more free coverage of the coronavirus pandemic, sign up for our Coronavirus Updates newsletter where all stories are free to read.

A new report suggests that children of all ages are susceptible to coronavirus infection and may also spread it to others — a finding likely to intensify an already fraught discussion about the risks of sending children back to school this fall.

The analysis, released Friday by the Centers for Disease Control and Prevention, details an outbreak at a sleep-away camp in Georgia last month in which 260 children and staffers — more than three-quarters of the 344 tested — contracted the virus less than a week after spending time together in close quarters. The children had a median age of 12. The camp had required all 597 campers and staff members to provide documentation that they had tested negative for the virus before coming. Staff were required to wear masks, but children were not.

While similar clusters have occurred around funerals, weddings, teenage parties and adult gatherings throughout the pandemic, few super-spreading events have been documented among children.

The report is likely to add fuel to an already polarizing nationwide discussion about whether sending children back to crowded school buildings is worth the risk, in large part because so little data has been available about children’s vulnerability to the infection and their ability to transmit the virus.

“To me, this is a significant weight added to the side of the scale that says close the schools,” said Andrew Noymer, an epidemiologist at the University of California at Irvine. While he added that children probably spend more time in close proximity at sleep-away camp than they do at school, “it’s solid evidence to suggest we should be extremely cautious about opening schools.”

The Trump administration has pushed in recent weeks for schools to reopen, while many states and major cities — including D.C. — have announced they will resume online-only to begin the year. “I do say again, young people are almost immune to this disease. The younger the better,” President Trump said Thursday during a White House briefing. “They’re stronger. They have a stronger immune system.”

Advocates of reopening schools for in-person instruction argue that early research shows children are less prone to infection and severe outcomes from the virus than adults are. While data continues to support that idea, little had been known about the extent to which children could transmit it — particularly when they are not showing symptoms.

According to the report released Friday, the outbreak at the camp, identified only as “Camp A,” suggests that children “might play an important role in transmission.”

“These findings demonstrate that SARS-CoV-2 spread efficiently in a youth-centric overnight setting, resulting in high attack rates among people in all age groups, despite efforts by camp officials to implement most recommended strategies to prevent transmission,” the report said.

“Asymptomatic infection was common and potentially contributed to undetected transmission, as has been previously reported. This investigation adds to the body of evidence demonstrating that children of all ages are susceptible to SARS-CoV-2 infection.”

The CDC released a separate statement with a headline about “the importance of CDC mitigation strategies,” rather than about the incident’s implications for viral transmission in children. The statement noted that by not requiring campers to wear masks or airing out cabins, the camp had not followed CDC reopening guidance, and it pointed to “daily vigorous singing and shouting” as potential contributing factors.

“Correct and consistent use of cloth masks, rigorous cleaning and sanitizing, social distancing, and frequent hand-washing strategies, which are recommended in CDC’s recently released guidance to reopen America’s schools, are critical to prevent transmission of the virus in settings involving children and are our greatest tools to prevent covid-19,” the statement read.

Caitlin Rivers, an epidemiologist at Johns Hopkins University, wrote in an email that she would like to see data from camps where children wore masks and whether they fared better.

“To me, this outbreak reinforces the importance of mitigation measures in classrooms and child-care settings,” Rivers wrote. “Physical distancing, mask use by students and teachers, hygiene and ventilation will all be critical to reducing risk for classrooms that do reopen in person.”

Noymer also noted that many school officials say they will require students, as well as teachers, to wear masks. But skeptics point out that children are unlikely to be diligent mask-wearers or social distancers, so reopening plans that include those measures in theory may not have them in actuality.

Authors of the CDC report noted that the study was limited by its data set, which includes tests of only 344 of the campers and staffers, and therefore could be missing cases. In addition, since Georgia experienced a jump in coronavirus transmission over the summer, some campers may have caught the virus before arriving. The CDC report acknowledged that it could not determine which campers did and did not adhere to recommendations for physical distancing, which also limits the kind of conclusions that can be drawn from the data.

Tara Smith, an epidemiologist at Kent State University, acknowledged that some data missing from the study — including detailed tracking of which infected children spent time around others and for how long — limits the extent to which the study can be used to draw specific conclusions, but it does suggest that more outbreaks could center on children the more they are in close proximity.

“I think what it shows is that kids definitely can be infected with this, apparently can spread this,” Smith said. “I think when we get kids back into their normal social networks, we’re going to see more of these.”

The Georgia camp had opened in two phases, according to the report: An orientation for 138 trainees and 120 staffers occurred June 17 through June 20. A total of 363 campers and three senior staffers joined on June 21. On June 23, a teenage staffer left after developing chills and subsequently tested positive for the coronavirus.

Camp officials began sending campers home June 24 and closed the camp on June 27.

Of those who were tested and came up positive, 231 were age 17 or younger; the remaining 29 were adults. Data about symptoms was available for only 136 patients: About a quarter, or 36 people, reported no symptoms; 100 children and staff members (74 percent) reported symptoms, including fever (65 percent), headache (61 percent) and sore throat (46 percent).