Question: Here’s a question that I’ve had for a few weeks, but I held back from asking since you were on vacation. 🙂 So I was reading news reports that in the last two weeks of July, ~100,000 children tested positive for COVID-19. Is this true?
Answer: Thanks for remembering your question and still asking! Short answer to your question is yes, these estimates are true, subject to the limitations of the underlying data used to conduct the analysis. And now the longer answer.
Cases, particularly cases among children, dramatically increased in mid/late July
In August, the American Academy of Pediatrics and the Children’s Hospital Association conducted an analysis to understand the scope of COVID-19 infections, hospitalizations, and deaths among children in the United States (where state-level age-specific data were available). Findings are summarized in Figure 1. One of the findings that generated a lot of news interest is that COVID-19 cases among children increased 40% in just 15 days — rising from a total 241,904 as of 7/15 to 338,982 as of 7/30.
When I read this astounding figure, I wondered how this compared to the rise in overall cases, regardless of age. So I ran a quick analysis using data from covidtracking.com and found that over the same 15 day period in mid/late July, total cases in the US increased 28%! To put that in perspective — the US has been reporting COVID cases every day since February 28th; so in just 15 days, we saw a nearly 30% increase in cases from the cumulative total of the previous 139 days! Whew! That’s exponential growth for you. What this also means is that cases among children were growing at a faster rate than cases among adults.
Cases among children are likely an underestimate
What’s also important to recognize is that the number of cases among children is likely an underestimate. Data presented last week in an article published in JAMA Pediatrics, “Clinical Characteristics and Viral RNA Detection in Children With Coronavirus Disease 2019 in the Republic of Korea” and further described in this accompanying editorial show that “not all infected children have symptoms, and even those with symptoms are not necessarily recognized in a timely fashion… This highlights the concept that infected children may be more likely to go unnoticed either with or without symptoms and continue on with their usual activities, which may contribute to viral circulation within their community.”
We have no national system for monitoring testing
One thing this analysis highlights is that the study authors had to laboriously collect testing data by age on a state-by-state basis with states reporting age distribution in different ways, using different definitions, and some states not reporting age distributions at all. Why should it be so difficult?! This lack of national testing data is unacceptable — it precludes other important analyses and insights. For example, we know that COVID disproportionately impacts Blacks, Hispanics, and American Indians. It would therefore be important to observe testing not only by age or race, but by age AND race. Data availability and completeness (not just for testing, but for cases and hospitalizations) in the US makes this type of analysis a shockingly challenging undertaking.
Figure 1. Children and COVID-19 as of 30 July (from AAP report)
