This seeks to examine the data available as of this writing (July 2020) regarding the rate of infection and transmission of the SARS-CoV-2 virus in the pediatric population, both from the United States and internationally.
Contact tracing is a practice where health department personnel try to identify people who might have come into contact (also known as contacts) with a person who might have an infectious disease. They try to trace back to the very first person (index patient) who started this chain of infectious cases.
A group of scientists from South Korea tried to analyze over 59,000 cases of COVID-19 from January to March 2020 to better understand who the pattern of spread of the disease. Household spread overall is significant at about 11.8% compared to the rate of non-house contacts at 1.9%. What that means is that one is much more likely to get it from someone else in the household than someone who is not. This is most likely reflection of the total amount of time spent in close quarters. Data has previously shown that without any masks, one’s risk of infection after being in close contact (defined as 15 minutes) with an infected person in an indoor environment with poor ventilation is about 25%.
When trying to extrapolate the data to the United States, the study has several limitations, namely time period during the pandemic (rising, stabilizing, decreasing), methods of mitigation (school closure) at the time, as well as differences in family demographics, societal, cultural, and familial interactions in Southeast Asia versus the United States.
Nonetheless, the data shown that children younger than 10
- Did not get infection very often, perhaps due to their limited interaction with society at large due to their young age, and
- Were less likely to spread infection to both their family members and others they came in contact with.
The data for children age 10-19 is quite different, with them more likely to spread it to their household contacts than any other age groups at almost 20%.
The vast majority of the cases are individuals in the 20-29 age groups. On the other hand, it seemed that they were less likely to spread it to others in their household.
Similarly, a smaller study on familial transmission in Switzerland involving 40 families revealed that in 79% of the hosueholds, more than “1 adult family member was suspected or confirmed for COVID-19 before symptom onset in the study child”. Children became ill first, i.e. as the index patient, in only 8% of the households.
In conclusion, it seems that children younger 10 are at much lower risk of getting and spreading the SARS-CoV-2 infection than most, both to their household and non-household contacts.