The implication is that this study contradicts the existing studies showing that children do not tend to be the index cases (sources of transmission) in COVID-19 transmission.
The study used contact tracing data from three COVID-19 outbreaks in child care facilities in Salt Lake County, Utah to retrospectively review attack rates and transmission patterns. 12 children in the child care facilities acquired COVID-19, and all had “mild or no symptoms.”
Three facilities are described. Facility A did not include any transmission to or from children. In Facility B, two children (8 months and 8 years old) had mild symptoms and “likely” transmitted COVID-19 to their parents. In Facility C, 8 students (6-10 years old) tested positive for COVID-19 and “likely” transmitted COVID-19 to contacts in their households. One mother “who was presumably infected by her asymptomatic child” was hospitalized, but no other information is available. The source for this cluster was not identified.
The report discusses 184 people associated with these 3 facilities. One was hospitalized, and none of them died. Most had mild symptoms, if any.
The report does not tell us definitively that any child acquired COVID-19 at the child care center or that they transmitted it to adults. The direction of transmission is always described as “likely,” based on timing. There doesn’t seem to be any attempt to rule out concurrent transmission to adults and children in settings outside the child care center. Every index case in the study was an adult.
Obviously children, especially symptomatic children, can transmit COVID-19 to adults, particularly within households. The real question is how efficiently they transmit and how that should affect policies around the operation of schools and day care centers, and this paper, with a very small number of instances of transmission from children to adults that appear to occur at home, doesn’t offer any new information on that question.