Not surprisingly, there has been far more study on this topic in adults as compared with children. This is largely because adults tend to suffer from more significant symptoms. Among adults with milder disease, the estimates are that 1-in-3 individuals suffer from long Covid. Those with more severe disease (i.e.: hospitalized) tend to suffer from long Covid at more than twice that rate.
If you are interested in some further reading on this topic in adults, feel free to peruse the following:
Hirschtick, et al. Clinical Infectious Diseases. Volume 73. Issue 11. December 2021. Pages 2055–2064.
Addressing the frequency of long Covid in children and adolescents has begun to gather more attention. Many of the early studies had results that indicated there should be some concern for long Covid in the age group. This included among those with very mild or no acute symptoms. The issue with these early studies was primarily their sample size which ranged from a few dozen patients to several hundred. A nice review article of many of these earlier studies was published at the end of 2021 by Zimmermann, et al. If you want to check a few examples of these earlier studies, the links below will take you there:
Trapani, et al. Italian Journal of Pediatrics. Volume 48. Article 83. June 2022.
Pooya, et al. World Journal of Pediatrics. Volume 17. September 2021. Pages 495–499.
Ashkenazi-Hoffnung, et al. Pediatric Infect Dis J. Volume 40, Issue 12. December 2021, Pages e509-e511.
Based on the results of the early studies raising the specter of concern for children and adolescents, a call out was made for larger studies. Some of these studies have emerged during 2022. The first two discussed below were both conducted in Denmark.
The first study, by Kikkenborg-Berg, et al, included 24,315 adolescents with positive tests along with 97,257 controls (i.e.: those without positive tests). This study concluded that those with positive tests had more long-lasting symptoms and required and increased quantity of sick leave. Nearly half (47.8%) of the case group reported new symptoms present 8 weeks post infection. The control group had a worse quality of life. Yep. That’s twice now.
There are a lot of limitations with this study. These include that it was based on questionnaires with a very long list of symptoms, a very low response rate to those questionnaires (about ¼ folks responded), potential bias as to whom responded based on demographic factors, and that different questionnaires were given to case and control groups.
The second study, conducted by Borch et al, included 37,522 case and 78,037 control subjects. Both children and adolescents were among the subjects of this study. They too found a substantial number of cases with reported symptoms (28%). However, they did something prior study did not do. Specifically, they looked for same parameters in the control group in the same manner as the case group (i.e.: same questionnaires for all). They also reported their data differently. Rather than stating that X% of cases had a symptoms and that it was statistically significant, they reported a residual percentage. By subtracting out the percentage of controls with symptoms, they found a residual percentage of 0.8%. This would mean that the rate of long Covid related symptoms in this age group may be closer to 1-in-100 in reality. And yes, you could look at the numbers in the first study and try to do those calculations on your own.
There is an ongoing study, known as the CLoCK study, in the UK. Preliminary results were released which stated that 14% of those positive for Covid had long Covid symptoms relative to controls at a 15-week endpoint. This study used questionnaires as well. Of the 220,000 that were sent out, only 17,000 resulted in a response. It will be interesting to see the data in all its glory once the study is completed.
I will wager that the answer is yes on this one. Even if it is 1% of the time, when you assume that every child and adolescent will get Covid, this is a ton of kids. We can debate how significant these symptoms are, how long they persist, and a litany of other aspects another time. And yes, there are other viruses such as EBV that can render a kid miserable for quite some time that we have known for awhile. So let us take this perspective going forward for purpose of discussion: long covid exists, roughly 1% get it, and it causes some level of discomfort for that 1%. With that perspective in mind…..Can we help prevent this outcome? At what cost?