A new article published in the journal Pediatrics suggests that long Covid may affect 5.8 million children in the United States. However, this estimate contrasts with other published estimates of pediatric long Covid, leading to the question of who is right.
The authors of the article reached their estimate by assuming that 20% of Covid-19 cases occur in children and that the prevalence of long Covid in children is 10-20%. According to data from the Kaiser Family Foundation, there were approximately 105 million Covid-19 cases in the U.S. by the end of January 2024. If 20% of those cases occurred in children and 20% of those children developed long Covid, then around 4.2 million children in the U.S. would be affected, which is relatively close to the number cited by the authors.
However, it is unclear how the authors determined that 10-20% of children with Covid-19 will develop long Covid. They state that experts reviewed relevant pediatric studies, but the selection process for these studies is unknown. Other researchers have proposed significantly lower prevalence rates for long Covid in children, such as 1.3% according to data from the Centers for Disease Control and Prevention (CDC). This discrepancy may arise from different populations being evaluated, different definitions of long Covid, and variability in study design.
The article in Pediatrics is a review rather than a study, providing an overview of the topic. It is not a systematic review or meta-analysis, which would require clear criteria for including and excluding literature. Without a standard definition for long Covid, it is difficult to compare the results of different studies.
Long Covid in children remains a significant public health concern, but the extent of the problem remains unknown. It is a complex issue with numerous reported symptoms and no clear predictions or relief strategies. Further research is needed to better understand the prevalence and impact of long Covid in children.