One Wyoming teenager said six months after being diagnosed with coronavirus she is still suffering from the effects of the illness and can only manage about half of her previous physical activity.

Madilyn “Maddie” Dayton, 13, told The Washington Post she used to go to school and still have energy to play sport with her friends, but now struggles to stay awake for Zoom classes.

Her mother said Maddie will “zonk out” at her computer and needs to be woken up despite being cleared for physical activity by her doctors.

Healthcare centres around the world have been monitoring the effects of coronavirus on children, The Scientist reported earlier this month. Data trickling in shows a growing number of cases of young children and adolescents suffering from ‘long COVID’.

The World Health Organisation (WHO) says growing evidence suggests the disease “can sometimes result in prolonged illness, even in young adults and children without underlying chronic medical conditions”.

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In the UK, 13 per cent of coronavirus patients under the age of 11, and 15 per cent of patients aged between 12 and 16, reported symptoms continuing for more than a month, the UK Office for National Statistics reported in February.

In Rome, more than half of the 129 surveyed caregivers reported their patients under the age of 18 said children had not completely recovered four months after returning positive coronavirus results. Another quarter of those children had three or more symptoms which continued for four months, according to preliminary evidence of long COVID in children published on medRxiv.

The preliminary evidence has not been peer reviewed, but researchers have used the early data as a signal that more evidence needs to be gathered on how the virus affects young patients.

The researchers working with the UK and Italian groups reported some of the children initially didn’t report symptoms – but went on to develop long-term symptoms.

MORE DATA REQUIRED

The data gathered by both groups lacks a control group, making it hard to determine whether different symptoms described, including nasal congestion, and fatigue, can be attributed to long COVID. However, studies in Rome and the UK are moving ahead following the early data.

“It’s waving a flag to say we need to pay attention to this and do more investigation,” Lara Danziger-Isakov, paediatric infectious disease specialist at Cincinnati Children’s Hospital, recently told Medscape Medical News.

In the UK, Terence Stephenson, a professor in child health at the University College London has been given a grant of $2.3 million to study the long COVID in children aged 11 to 17.

“I don’t have a scientific view on what long COVID is in young people … because frankly, we don’t know,” Professor Stephenson said of the study.

His preliminary results are expected in June 2021.

Danilo Buonsenso, a paediatric infectious disease physician at Gemelli University Hospital, who led the preliminary study in Rome, said current data is “lacking”.

Dr Buonsenso’s team will also be conducting a formal study into long COVID in children.