Children Are Not Super-spreaders of COVID-19

A look at COVID-19 in Children and Schools Around the World

Michelle Cretella, MD, August 11, 2020

This August, the normal back to school rush of planning, gathering school supplies, and excitedly looking forward to the next year of learning and extracurricular activities is nowhere to be found. Instead, thanks to the COVID-19 pandemic, government and school officials, parents, students and teachers are facing this back to school season with varying degrees of fear and trepidation. There is time-tested, scientific evidence that in-person learning is the optimal environment for children, and therefore should be the model to which school districts around the country aim to return safely. Fortunately, research concerning COVID-19 and youth is providing some welcomed good news. There is now sufficient scientific evidence from around the world to enable local communities in America to confidently plan a return to in person learning. While there is no one size fits all protocol to a return to brick-and-mortar schools, significant comfort may be found in the facts.  

Around the world, a return to school is proving to be an attainable, safe option as a default for school districts. It is evident that unlike the flu, children are not super-spreaders of COVID-19. Children do not get nor pass on this virus as easily as other respiratory viruses like influenza. In fact, children only account for only 7.6% of U.S. COVID-19 cases. Nationwide, there have only been 200,184 total child COVID-19 cases reported. In addition, the severity of the virus in children is significantly less than that of adults. Only 0.7%-9.1% of pediatric cases in America resulted in hospitalizations, and the large majority of hospitalized children were under one year old with underlying conditions; not school-aged children. Taking a look at this data in context, the CDC reported 36 COVID-19 deaths in children 0-14 years old1, 185 pediatric deaths due to influenza in the 2019-2020 flu season in children 0-18 years old2, and 11,964 deaths from all other causes in children 0-14 years old. Worldwide, children under 18 have accounted for less than 2% of COVID-19 cases. Unlike other viral respiratory infections, children are not a major vector of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. The cause of most pediatric coronavirus cases is family transmission, where children and parents are in very close quarters, and it is most often passed from parent to child. While we know that children do contract and spread COVID-19, there is very little evidence of child-to-child or child-to-adult transmission outside of the family unit.3 

A study on child-to-adult transmission in South Korea found that household contacts of index cases in children between the ages of 10-19 had a 18.6% rate of positivity as reported by the CDC. So, children as first infected cases in families are capable of transmitting the virus to other family members, however, does this mean there is a significant risk of transmission in schools? Not necessarily. Researchers in New South Wales, Australia found that “data from both virus and antibody testing to date suggest that children are not the primary drivers of COVID-19 spread in schools or in the community.”4 Children under 19 account for only 4% of COVID-19 cases, yet are only 23% of the population in New South Wales. In regard to schools, there were 18 confirmed cases in 15 schools that only resulted in two additional transmission cases among 881 close contacts. 

Antibody tests have become a way to more clearly identify the rate of spread in communities. Researchers at the University Hospital in Dresden conducted the largest study  in Germany on school children and teachers. They included antibody testing at schools in communities where there were large coronavirus outbreaks. Blood samples from approximately 1,500 children between the ages of 14 to 18 years, and 500 teachers from 13 schools in Dresden and the districts of Bautzen and Goerlitz in May and June were tested. Only 12 individuals had antibodies, giving no evidence that school children play a role in spreading the virus particularly quickly. During a news conference, the lead researcher of the study, Dr. Berner, posited that “children may even act as a brake of infection,” saying that infections in schools had not led to an outbreak, while the spread of the virus within households was also less dynamic than previously thought. 

Dr. Mark Woolhouse, a leading epidemiologist and member of the British government’s Sage committee stated that “there has been no recorded case of a teacher catching the coronavirus from a pupil anywhere in the world.” He told The Times that it may have been a mistake to close schools in March given the limited role children play in spreading the virus. However, there was limited knowledge of the spread of the virus at the time, so a temporary closure was appropriate from a precautionary standpoint. 

A great comparison to consider is research gathered from the Public Health Institute of Sweden and the Finish Institute for Health. Sweden kept their schools open whereas Finland closed their schools. Both countries reported zero COVID-19 deaths in children 1 to 19 years old. They each concluded that closing schools had no measurable effect on the number of pediatric cases and that children are not a major risk group for COVID-19 and seem to play a minor and even negligible role in transmission. In addition, Sweden saw no increased risk of COVID-19 infection among teachers versus other professions.5

According to pediatric infectious disease specialists, Drs. Benjamin Lee and William Raszka, “Children, particularly school-aged children, are far less important drivers of SARS-CoV-2 transmission than adults.” A critical point to consider is the immense and increasing number of other serious costs associated with not re-opening schools and forcing children to remain in isolation. “Serious consideration should be paid toward strategies that allow schools to remain open, even during periods of COVID-19 spread. [We need to] minimize the potentially profound adverse social, developmental, and health costs that our children will continue to suffer until an effective treatment or vaccine can be … distributed or, … until we reach herd immunity.”6 

Based on this research, it is appropriate to conclude that it is safe to re-open schools. However, strategies will need to vary locally based on the present situation in each area across the country. With the exception of Sweden, which avoided shutting schools but did have students over age 15 learn virtually, every other country has re-opened schools with COVID-19 mitigation strategies. Some examples of this include staged reopenings, learning in stable pods, holding some classes outdoors, indoor social distancing, hybrid models allowing half the student population in buildings at any one day, increased cleaning, and masks (which are optional in some countries and mandated in others). 

The scientific evidence currently available cannot offer a best approach for all schools in all localities, and distance learning should remain an option for vulnerable youth and families. However, there appears to be sufficient evidence to say that it is now time to pursue avenues of safe reopening. For the sake of our children and communities, school districts around the country should prioritize re-opening schools as the default option, while providing safe alternatives for our vulnerable population. Let us not lose hope that this pandemic will eventually come to an end and we will see a return to normalcy one day. 


References 

1.  COVID-19 Provisional Counts - Weekly Updates by Select Demographic and Geographic Characteristics. CDC.gov. https://www.cdc.gov/nchs/nvss/vsrr/covid_weekly/index.htm#AgeAndSex. Published 2020. Accessed July 31, 2020.

2.  Influenza-associated Pediatric Mortality. Gis.cdc.gov. https://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html. Published 2020. Accessed July 31, 2020. 

3.  Posfay-Barbe KM, Wagner N, Gauthey M, Moussaoui D, Loevy N,  et al. COVID-19 in Children and the Dynamics of Infection in Families. Pediatrics Jul 2020, e20201576; DOI: 10.1542/peds.2020-1576

4. http://ncirs.org.au/sites/default/files/2020-04/NCIRS%20NSW%20Schools%20COVIDSummaryFINA

5. http://ncirs.org.au/sites/default/files/2020-04/NCIRS%20NSW%20Schools%20COVIDSummaryFINA

6.  Lee B and Raszka WV. COVID-19 Transmission and Children: The Child Is Not to Blame. Pediatrics Jul 2020, e2020004879; DOI: 10.1542/peds.2020-004879