A large U.S. study conducted on children found that only four percent of them were infected with coronavirus, and the vast majority of these cases were asymptomatic or mild. The study confirmed but did not explain, the great mystery of the pandemic – why the infection that has killed a million and a half people in the world so far is rare and almost harmless among younger children.
For the study, published in the journal JAMA Pediatrics, the researchers reviewed data from 136,000 pediatric patients in seven U.S. children’s hospitals, all of whom were tested for coronavirus. There were 5,374 children positively (3.9 percent), and among them, less than seven percent developed more severe symptoms that ended up in the hospital. Eight died, most with previous complex comorbidities, meaning the mortality rate was 0.15 percent.
The infection was more frequent and more severe among black, Hispanic, and Asian patients, among adolescents from 12 to 17 years of age, those who have basic insurance, and some previous chronic disease.
The authors add that further research will be needed to determine which medical conditions put children at greater risk. The study found that children with diabetes, rather than asthma, would be more likely to test positive. It is also unclear why children are barely affected by coronavirus to the greatest extent. One theory promoted by some studies suggests that children’s nasal mucosa cells produce fewer proteins that help the virus enter the body compared to the nasal mucosa of adults.