How Does Children Contribute to the Spread of COVID-19?

As more and more schools, kindergartens, and childcare centers re-open across the US, one topic that continues to pop up is whether children below the age of 18 (and especially younger children) can catch and spread SARS-CoV-2, the novel coronavirus that causes COVID-19.

The following is stated on the American Academy of Pediatrics' (AAP) website:

"Although children and adolescents play a major role in amplifying influenza outbreaks, to date, this does not appear to be the case with SARS-CoV-2. Although many questions remain, the preponderance of evidence indicates that children and adolescents are less likely to be symptomatic and less likely to have severe disease resulting from SARS-CoV-2 infection. In addition, children may be less likely to become infected and to spread infection."

It is important to note that scientists the worlds over are still learning about SARS-CoV-2 since the virus is so new, and evidence that either support or contradict the above highlighted line from the AAP is still growing.

A new study (Park, et. al.) that came out of South Korea, where they analyzed 59,073 contacts of 5,706 COVID-19 index patients reported in South Korea during January 20–March 27, 2020, found some interesting statistics regarding how children helped spread the virus:

"We also found the highest COVID-19 rate (18.6% [95% CI 14.0%–24.0%]) for household contacts of school-aged children and the lowest (5.3% [95% CI 1.3%–13.7%]) for household contacts of children 0–9 years in the middle of school closure. Despite closure of their schools, these children might have interacted with each other, although we do not have data to support that hypothesis. A contact survey in Wuhan and Shanghai, China, showed that school closure and social distancing significantly reduced the rate of COVID-19 among contacts of school-aged children (8). In the case of seasonal influenza epidemics, the highest secondary attack rate occurs among young children (9). Children who attend day care or school also are at high risk for transmitting respiratory viruses to household members (10). The low detection rate for household contacts of preschool-aged children in South Korea might be attributable to social distancing during these periods. Yet, a recent report from Shenzhen, China, showed that the proportion of infected children increased during the outbreak from 2% to 13%, suggesting the importance of school closure (11)."

However, the AAP's own journal published a paper (Lee et. al.) which reviewed cases of transmission around the world from first half of 2020 and concluded that:

"Almost 6 months into the pandemic, accumulating evidence and collective experience argue that children, particularly school-aged children, are far less important drivers of SARS-CoV-2 transmission than adults. Therefore, serious consideration should be paid toward strategies that allow schools to remain open, even during periods of COVID-19 spread."

In contrast, another recent paper (Heald-Sargent et. al.) out of Chicago, which analyzed 145 patients aged less than one month to 65 years old, concluded that:

"However, young children had significantly lower median (interquartile range) CT values (6.5 [4.8-12.0]), indicating that young children have equivalent or more viral nucleic acid in their upper respiratory tract compared with older children and adults (Figure). The observed differences in median CT values between young children and adults approximate a 10-fold to 100-fold greater amount of SARS-CoV-2 in the upper respiratory tract of young children."

This study indicates that younger children may carry significantly higher viral loads in their upper respiratory tract when compared to adults, which may contribute to viral spread.

Many of us have also read the headlines recently of a Georgia summer camp where younger children were attendees and older children were staff members suffering a rather large outbreak where over 200 individuals were infected (44% attack rate). A study (Szablewski et. al.) has been published regarding this event, which concluded that:

"These findings demonstrate that SARS-CoV-2 spread efficiently in a youth-centric overnight setting, resulting in high attack rates among persons in all age groups, despite efforts by camp officials to implement most recommended strategies to prevent transmission. Asymptomatic infection was common and potentially contributed to undetected transmission, as has been previously reported (1–4). This investigation adds to the body of evidence demonstrating that children of all ages are susceptible to SARS-CoV-2 infection (1–3) and, contrary to early reports (5,6), might play an important role in transmission (7,8)."

As more scientific evidence is gathered as schools reopen across the country and the world, it is my personal opinion that children can spread SARS-CoV-2 just as easily as adults, and the lower viral attack rates in children seen in studies from earlier in the year are due to 1. schools were locked down the world over, thus limiting spread of SARS-CoV-2 in children, and 2. children are much more likely to be asymptomatic and suffer from mild disease states, thus they are less likely to be tested and contribute to the statistical pool.

It should also be noted that although children generally do not suffer severe symptoms often seen in adults, some may still develop strong immune responses which in rare cases, may afflict them with a Kawasaki-like disease (now acknowledged by and referred to as MIS-C by the CDC).

The AAP is certainly correct in indicating that prolonged school closures may result in significant mental health impacts as well as adverse learning outcomes in children, however, we must be prudent and not rush to re-open schools unless our schools are both financially and materially ready to do so. As despite the fact that the majority of children may suffer from light to no symptoms if they are infected with SARS-CoV-2, they may still transmit the virus readily to their teachers, school staff, as well as their family members. We must take into account that older adults remain the most vulnerable population (a recent article from the Washington Post highlighted the impact of COVID-19 on teachers from an Arizona school system trying to re-open), and take into account the health and mental well-being of not just our children but our teachers as well.

As always, if you have any questions or would like to request a consultation regarding the safe reopening of a school or childcare location, please contact us.