Studies continue to show very low incidence of CV-19 infection in children. In this study, 33,041 children who came in for routine care at 28 children’s hospitals across the country were tested for CV. All were asymptomatic at the time of testing. There were only 250 positive results. That is a .75% incidence. And given the controversy about PCR test results, we should be told what cycle number was used in the testing. (JAMA Article)
Another study related to children comes from South Korea. (JAMA Article) The authors were primarily looking at how long viral RNA was detected in children and could potential cases in children be identified by symptoms. 91 children were studied for an extended period of time. 22% were asymptomatic throughout. Only 2 had what was described as severe illness, although even then all that meant was they required some supplemental oxygen. Only 14 were treated in any way. 66% did not have symptoms that were recognized before diagnosis. The average length of time viral RNA was detected was 17.6 days after diagnosis. No attempt to ascertain if this was just viral fragments and whether it was viable by culture. But, and we now know this is important, the cycle time for the PCR test was 40 cycles–too high. At 35 cycles, the length of detection drops below 15 days, and at 30 cycles it drops to around 12 days. The authors tried to suggest that the results mean children could be asymptomatic spreaders, but gave no separate information on cycle times for the asymptomatic children. I am betting they were not infectious.
Finally, a study from the UK on characteristics of children admitted to the hospital with CV-19. (BMJ Study) 651 children under the age of 19 and admitted to 138 hospitals were included. This was less than 1% of all patients hospitalized in the country for CV-19. Six patients died in the hospital, all of whom had “profound” comorbidities. Three were infants born very prematurely, whom I suspect picked up the virus in the hospital. So healthy children had zero risk of dying. Most of the children were under the age of 5. 42% had at least one comorbidity.
Collectively these studies continue to fill in the picture that children are rarely sickened by CV-19 and really are not likely to be playing a significant role in transmission. We need to let them return to a normal school and social life.