Research published over the past two weeks sheds some new light on how the novel coronavirus spreads among children—and highlights some concerning findings on how the virus can affect them.
Coronavirus cases among children rose sharply in July
One report, published July 30 by the American Academy of Pediatrics and the Children's Hospital Association, suggests that coronavirus transmission among children accelerated last month.
The report is based on publicly reported data from 49 states; Guam; New York City; Puerto Rico; and Washington, D.C. While most of those areas defined a child as a person no older than 19 or 17, Alabama defined a child as a person no older than 24, and Florida and Utah each defined a child as a person no older than 14.
According to the report, the number of children who tested positive for the coronavirus increased by 40% from July 16 to July 30. During that time, a total of 97,078 children tested positive for the coronavirus, increasing the total number of U.S. children who had tested positive for the virus from 241,904 as of July 16 to 338,982 as of July 30, the report stated.
The report noted that more than a quarter of the total number of reported coronavirus cases among U.S. children as of July 30 were reported during the last two weeks of July. Alaska, Idaho, Missouri, Montana, Nevada, and Oklahoma saw the highest increases of new coronavirus cases among children during those two weeks, while New York City, New Jersey, and other states within the Northeast saw the lowest increases, according to the report. Arizona reported the most new coronavirus cases per 100,000 children during those two weeks, at over 1,000.
Overall, the total number of reported coronavirus cases among U.S. children represented 8.8% of all U.S. coronavirus cases that were reported as of July 30, according to the report. The report states that, as of July 30, the numbers of reported coronavirus cases among children comprised 10% or more of total cases reported in each of 25 states. In comparison, the numbers of reported coronavirus cases among children in New Jersey and New York City comprised less than 3% of total cases reported in those areas.
Children have similar risk of severe Covid-19 as adults—which has implications for schools, CDC says
Separately, CDC on Friday released a new Morbidity and Mortality Weekly Report that shed light on how the novel coronavirus can affect children who become infected.
For the report, researchers reviewed data on hospitalizations among children with Covid-19, the disease caused by the coronavirus, from 14 states that was collected between March 1 and July 25.
The researchers found that children with Covid-19 were much less likely to be hospitalized than adults, with a hospitalization rate of about eight per 100,000 children compared with a rate of about 164.5 per 100,000 adults.
However, when children with Covid-19 were hospitalized, their risk of developing a severe case of the disease and needing intensive care was around the same as adults, at a rate of about one in three children with Covid-19 being cared for in the ICU. The rate of children with Covid-19 who were treated with a ventilator was considerably lower than the rate among adults, though, at about 5.8% and 18.6%, respectively.
According to the report, children ages 12 to 17 comprised the majority of those hospitalized with Covid-19, at 41.8%, followed by children ages:
- Zero to two months, at 18.8%;
- Five to 11 years, at 16.8%;
- Two to four years, at 8.7%;
- 12 to 23 months, at 5.4%;
- Six to 11 months, at 5%; and
- Three to five months, at 3.5%.
The researchers had information regarding whether 222 children participating in the report who were hospitalized for Covid-19 had underlying health conditions. Of those children, about 42% had at least one underlying health conditions.
Information regarding a child's race was reported for 526 of the children included in the report. Of those, about 46% were Hispanic and almost 30% were Black. The researchers found that Black children were five times more likely than white children to be hospitalized with Covid-19, while Hispanic children were eight times more likely to be hospitalized with Covid-19 than white children. However, they wrote, "Reasons for disparities in Covid-19-associated hospitalization rates by race and ethnicity are not fully understood." The researchers called for greater efforts to understand the societal factors that affect health to help mitigate racial and ethnic disparities in pediatric Covid-19 hospitalization rates.
Overall, the researchers said their findings show that "[c]hildren are at risk for severe Covid-19"— which has implications for schools and childcare centers that are looking to reopen. "Reinforcement of prevention efforts is essential in congregate settings that serve children, including childcare centers and schools," the researchers wrote.
Nearly 600 children have been hospitalized with coronavirus-linked inflammatory syndrome
And in a separate Morbidity and Mortality Weekly Report that CDC released Friday, researchers found that at least 570 children were admitted to U.S. hospitals as of July 29 with a life-threatening, multi-system inflammatory syndrome that has been linked to the novel coronavirus.
The syndrome, known as MIS-C, is a rare but severe disease that has been reported in both young children and adolescent patients who were infected with the coronavirus, including some who didn't know they had been infected with the virus. In children who were infected with the virus and develop MIS-C, the condition typically manifests around two to four weeks after infection, CDC said. MIS-C shares symptoms similar to toxic shock and Kawasaki disease, including fever, rashes, swollen glands, and heart inflammation.
CDC's report is based on data collected from 40 state health departments, the District of Columbia, and New York City. According to the report, clinicians from those areas as of July 29 had reported a total of 570 cases of MIS-C among hospitalized children. Among 565 of those children who were tested for the coronavirus, 100% tested positive. The remaining five patients were not tested for the virus, but providers believed there was an epidemiologic link between their cases of MIS-C and the coronavirus, according to CDC. All of the children developed MIS-C between March 2 and July 18. Of the 570 patients, 63.9%, were admitted to an ICU and 10 of the patients died. About two-thirds of the patients had no pre-existing medical conditions, CDC said.
The ages of the patients ranged from two weeks to 20 years, with a median patient age of eight years, CDC said. According to the report, 40.5% of the patients were Hispanic, 33.1% were Black, and 13.2% were white.
CDC in the report said as new cases of the novel coronavirus continue increasing across the United States, cases of MIS-C among children could rise, as well. But the agency warned that corresponding increases in cases of MIS-C may not be apparent immediately, as the condition typically takes between two to four weeks to develop in children who contract the coronavirus. As such, CDC urged health care providers to "continue to monitor patients to identify children with a hyperinflammatory syndrome with shock and cardiac involvement" and to report suspected cases of MIS-C to their local and state health departments (Janes, Washington Post, 8/10; New York Times, 8/10; Janes, Washington Post, 8/7; Chander, Reuters, 8/7; AAP/CHA report, 7/30; CDC Morbidity and Mortality Weekly Report , 8/7; CDC Morbidity and Mortality Weekly Report , 8/7).