Its been clear for some time that post-COVID conditions, also known as long COVID, are more commonly seen in adults than in children, but the true incidence of long COVID in kids was unknown. However, a new international study has finally shed some light on how many kids get long COVID, and which pediatric COVID patients are most at risk.

Researchers at the University of Calgary in Canada examined data collected from 36 emergency departments in eight countries. The families of 1,884 children who tested positive for COVID while in the emergency room were contacted 90 days later and asked about post-COVID conditions defined as persistent, new, or returning symptoms or health problems associated with the condition that brought them to the emergency department.

Overall, 5.8% of children who had tested positive for COVID reported post-COVID conditions. Rates were higher in children who ended up being hospitalized for 48 hours or more, who reported four or more symptoms in their initial visit to the emergency department, or who were ages 14 and up.

Approximately 9.8% of children who were hospitalized for 48 hours or more reported post-COVID conditions, while 4.6% of those who were discharged from the emergency room reported post-COVID issues. Researchers also found that children who were hospitalized and experienced severe outcomes within 14 days were more likely to report symptoms 90 days later than hospitalized children with less serious illness.

The most frequently reported symptom among children was fatigue or weakness, followed by cough and difficulty breathing or shortness of breath. All of these are also symptoms commonly reported by adults with post-COVID conditions.

Our results suggest that appropriate guidance and follow-up are needed, especially for children at high risk for long COVID, Dr. Stephen Freedman, the studys principal investigator, said in a statement .

Our finding that children who had multiple COVID-19 symptoms initially were at higher risk for long COVID is consistent with studies in adults, said Dr. Todd Florin, co-principal investigator of the study.

Unfortunately, there are no known therapies for long COVID in children and more research is needed in this area, Florin said. However, if symptoms are significant, treatment targeting the symptoms is most important.

Its worth noting that all the children enrolled in the study had been brought to emergency departments, so they may have been more likely to exhibit serious symptoms. Its also possible that some children were brought to the emergency room for an unrelated issue and tested positive for COVID while they were there. Regardless, the study shows that children who were sicker, as indicated by their hospitalization or the number of symptoms they reported, were more likely to report post-COVID conditions 90 days later.

Researchers followed a separate group of children who were seen in the ER but tested negative for COVID, and some of these children (5% of those hospitalized and 2.7% of those discharged from the ER) also reported symptoms such as fatigue, weakness and shortness of breath 90 days after they were seen in the emergency department.

Data from the study shows that post-COVID conditions such as these were reported approximately twice as often among children who had tested positive for COVID, compared to children whod tested negative.

What all of this means for parents

Because of this study, we may be able to predict which kids are at risk for long COVID, Dr. Candice Jones, a board-certified pediatrician not affiliated with the study, told HuffPost.

Jones also noted that the rate of post-COVID conditions in children that researchers found is much lower than the rate among adult patients.

In addition to hand-washing and masking, vaccination protects children from all COVID-related risks. COVID vaccines are now available to all children ages 6 months and up. Millions of children in the U.S. have received COVID vaccinations, which both the Centers for Disease Control and Prevention and the American Academy of Pediatrics note are safe and effective.

We know vaccination can prevent COVID infection, prevent severe illness, prevent hospitalization and death thus minimizing the childs risk for long COVID, Jones said.