Older children spread the coronavirus just as much as adults, large study finds

A large new study from South Korea indicates that children younger than age 10 years transmit the novel coronavirus to others much less often than adults do, while those aged 10-19 years can spread the virus to at least the same degree as adults. Researchers identified 5,706 people in South Korea who were the first to report COVID-19 symptoms in their households between January 20 and March 27, when schools were closed, and then traced 59,073 contacts of these “index cases.” The researchers tested all of the household contacts of each patient irrespective of symptoms, and only tested symptomatic contacts outside the household. Children younger than age 10 years were found to be about one-half as likely as adults to spread the virus to others, possibly because children generally exhale less air or because they exhale that air closer to the ground. The study warns, however: “Young children may show higher attack rates when the school closure ends, contributing to community transmission of COVID-19.” Children in middle and high school were found to be even more likely to infect others than adults were, possibly because of their behaviors, according to experts. Michael Osterholm, PhD, MPH, an infectious diseases expert at the University of Minnesota, observes: “We can speculate all day about this, but we just don’t know. The bottom line message is: There’s going to be transmission.”