Children who develop COVID-19 rarely experience symptoms that last longer than 4 weeks, according to a large UK study published in The Lancet Child and Adolescent Health (1). In fact, fewer than one in 20 children with COVID-19 has long-term symptoms.
Researchers from King’s College, London, analysed daily reports from the ZOE COVID Symptom Study app from March 2020 to February 2021. This period included the reopening of schools in the autumn and the peak of the winter wave. Entries, typically filled in by parents or carers, covered more than 250,000 children aged 5-17, including 7,000 experiencing COVID-19 symptoms.
For this analysis, the researchers used reports from 1,734 children who were positive for COVID-19 and had a clear start and end to their symptoms. With regular reports until they were healthy again, the team calculated the duration of illness and type of symptoms for each child.
On average, younger children (5-11 years old) were ill for five days and older children (12-17 years old) were sick for seven days. Overall, fewer than one in 20 was ill for more than 4 weeks, and only one in 50 has symptoms for over 8 weeks. Older children were marginally more likely to have symptoms for 4 weeks, but there were no differences after 8 weeks. This is in stark contrast with adults, where one in 7 can experience symptoms for more than 4 weeks and one in 20 for 8 weeks or more.
“We know from other studies that many children who catch coronavirus don’t show any symptoms at all; and it will be reassuring for families to know that those children who do fall ill with COVID-19 are unlikely to suffer prolonged effects”, said Prof Emma Duncan, based at King’s College London. “However, our research confirms that a small number do have a long illness duration with COVID-19, though these children too usually recover with time. We hope our results will be useful for doctors, parents, and schools caring for these children – and of course, affected children themselves.”
Like in adults, the most common symptoms in children included headaches, fatigue, sore throat and loss of smell. Most experienced six to eight different symptoms during their illness, but it had dropped to only two symptoms after 4 weeks. Blissfully, there were no reports of children experiencing neurological symptoms, such as seizures, impaired concentration, or anxiety.
During their analysis, researchers also looked at the children with a negative test for COVID-19 but with similar symptoms, possibly indicating other conditions, such as a cold and flu. Children with a positive COVID-19 test had symptoms for 3 days longer and were more likely to still had symptoms after 4 weeks compared to children with a negative test. However, for those still with symptoms after 4 weeks, children with a negative test were more likely to feel worse and have more severe symptoms.
From these results, the team pointed out that, although common infectious diseases have been low due to social distancing, it is highly likely that they will be back when restrictions are lifted. While most children recover quickly, childhood infections can cause long-term symptoms, and a surge in cases should be considered when planning child services after the pandemic.
“This research highlights the importance of the data that thousands of parents and carers have contributed on behalf of their children”, concluded Prof Tim Spector, ZOE COVID Symptom Study lead. “These insights are only possible through large-scale community data science, and we’re grateful to everyone who has taken a minute or two out of their busy days to log the health of themselves and their family during the pandemic.”
(1) Molteni E, Sudre C, Canas L, Bhopal S, Hughes R, Antonelli M, Murray B, Klaser K, Kerfoot E, Chen L, Deng J, Hu C, Selvachandran S, Read K, Capdevila J, Hammers A, Spector T, Ourselin S, Steves C and Modat M (2021) Illness duration and symptom profile in symptomatic UK school-aged children tested for SARS-CoV-2. The Lancet Child and Adolescent Health DOI:https://doi.org/10.1016/S2352-4642(21)00198-X