Children infected with COVID-19, but not hospitalised, may still experience long COVID symptoms up to three months after infection, finds a study.

Past research has revealed that children and adults hospitalised with COVID-19 are more susceptible to developing long COVID symptoms.

The study by researchers at the University of Texas Houston examined 1,813 volunteers between the ages of 5 and 18. Of these, 82 children reported having long COVID symptoms. 1.5 per cent showed symptoms that lasted between four and 12 weeks, including loss of taste and smell, fatigue, and cough.

An additional 3.3 per cent reported that symptoms such as loss of taste and smell, cough, and difficulty breathing persisted for longer than 12 weeks. Further, of those who reported symptoms past 12 weeks, the unvaccinated and obese children had a higher chance of developing long COVID, revealed the study published in The Pediatric Infectious Disease Journal.

"These findings are consistent with other literature that found children and adults who have comorbid health conditions and are unvaccinated are at a higher risk of being hospitalised for the virus," said Sarah Messiah, Professor of epidemiology, human genetics, and environmental sciences at UTHealth School of Public Health-Dallas.

In addition, researchers found that children infected with COVID-19 before the emergence of the Delta variant were more at risk of developing long COVID.

"If you had COVID-19 earlier in the pandemic, you were more at risk for longer symptoms. With Delta and Omicron, we did see a lot of children who ended up hospitalised, but their symptoms were less severe, and our results show they were also less likely to report persistent symptoms too," Messiah said.

The results, Messiah said, are important because it highlights the presence of non-hospitalised youth who may also experience persistent long COVID symptoms after infection.

"There may be a perception that one needs to be hospitalised to have long COVID, and that is not what we found. I encourage parents to still take caution and get their child vaccinated against COVID-19 because we now know that it will decrease the risk of infection and long COVID," she said.