Largest Study to Date Reports Long COVID Symptoms in Children up to 14 Years Old

The largest study to date of long COVID symptoms in children ages 0 to 14 confirms that children who have been diagnosed with COVID-19 can experience long COVID symptoms that last at least two months.

The study, published in The Lancet Child & Adolescent Health , used a nationwide sampling of children in Denmark and compared positive COVID-19 cases to a control group of children with no history of COVID-19 infection.

“The overall goal of our study was to determine the prevalence of long-lasting symptoms in children and infants, along with quality of life and school or daycare absenteeism. Our results reveal that although children with a positive COVID-19 diagnosis are more likely to experience lasting symptoms than children without a prior COVID-19 diagnosis, the pandemic has affected all aspects of the lives of all young people. It will be important to continue investigating the long-term consequences of the pandemic on all children,” says Professor Selina Kikkenborg Berg, Copenhagen University Hospital, Denmark.

Most previous studies of long COVID in young people have focused on adolescents, with infants and toddlers rarely represented. In this research, surveys were sent to the mother or guardian of children between 0-14 years old who had tested positive for COVID-19 between January 2020 and July 2021. In total, responses were received from almost 11,000 children with a positive COVID-19 result. of the test who were matched by age and sex with more than 33,000 children who had never tested positive for COVID-19.

The surveys asked participants about the 23 most common symptoms of long COVID in children (identified by the January 2021 Long COVID Children’s Rapid Survey) and used the World Health Organization’s definition of long COVID as symptoms. that last more than two months.

• The most common symptoms among children ages 0 to 3 were mood swings, rashes, and stomach pains.
   
• Between ages 4 and 11, the most common symptoms were mood changes, difficulty remembering or concentrating, and rashes, and between ages 12 and 14, fatigue, mood swings, and difficulty remembering or concentrating.

Study results found that children diagnosed with COVID-19 in all age groups were more likely to experience at least one symptom for two months or longer than the control group.

In the 0-3 age group, 40% of children diagnosed with COVID-19 (478 of 1,194 children) experienced symptoms for more than two months, compared to 27% of controls (1,049 of 3,855 children ).

For the age group of 4 to 11 years the relationship was 38% of cases (1,912 of 5,023 children) compared to 34% of controls (6,189 of 18,372 children), and for the age group of 12 to 14 years , 46% of cases (1,313 of 2,857 children) compared to 41% of controls (4,454 of 10,789 children) experienced lasting symptoms.

The types of non-specific symptoms associated with long COVID are often experienced by otherwise healthy children; Headache, mood swings, abdominal pain and fatigue are symptoms of common ailments experienced by children that are not related to COVID-19.

However, this study revealed that children with a positive COVID-19 diagnosis were more likely to experience long-lasting symptoms than children who had never had a positive diagnosis, suggesting that these symptoms were a presentation of long COVID . This is supported by approximately one-third of children who test positive for COVID-19 experiencing symptoms that were not present before SARS-CoV-2 infection. Furthermore, with increasing duration of symptoms, the proportion of children with these symptoms tended to decrease.

Overall, children diagnosed with COVID-19 reported fewer psychological and social problems than children in the control group. In older age groups, cases often felt less scared, had fewer problems sleeping, and felt less worried about what would happen to them. One possible explanation for this is increased pandemic awareness in older age groups, with children in the control group experiencing fear of the unknown disease and a more restricted daily life due to protecting themselves from contracting the virus.

“The window to undertake such research is rapidly closing as the vast majority of children have now had a COVID-19 infection, for example 58% of children in Denmark had a laboratory-confirmed infection between December 2021 and February 2022. The burden in SARS-CoV-2-positive children is essential to guide clinical recognition, parental care, and social decisions about isolation, confinement, non-pharmaceutical interventions, and safety strategies. vaccination,” says Professor Selina Kikkenborg Berg.

“Our findings align with previous studies of long COVID in adolescents showing that although the chances of children experiencing long COVID are low, especially compared to control groups, they should be recognized and treated seriously. “More research will be beneficial to better treat and understand these symptoms and the long-term consequences of the pandemic in children in the future.”

The authors acknowledge some limitations of the study, including a long recall period between diagnosis and completion of the survey. The research relied on parent-reported data, which is less accurate for psychological symptoms. This can also lead to selection bias, as mothers and guardians of children with more severe symptoms are often more willing to respond, leading to the results representing the most affected children. Additionally, public COVID-19 testing was only available starting in August 2020, meaning some children in the control group could have had undetected asymptomatic infections.

Writing in a linked comment, Maren Rytter of the University of Copenhagen, Denmark, who was not involved in the study, said: “[Although] the study found that symptoms of any kind were slightly more frequent in children who had been infected with SARS-CoV-2, the overall impact on children from having had COVID-19 is probably small and probably much smaller than the impact of the indirect effects of the pandemic. For most children with non-specific symptoms after COVID-19, the symptoms are more likely to be caused by something other than COVID-19, and if they are related to COVID-19, they are likely to be caused by something other than COVID-19. disappear over time."