A large UK study has for the first time detailed COVID-19 illness in symptomatic children aged 5 to 17. The study included data on 1,734 children. Studies show that children with COVID-19 usually recover within a week with fewer symptoms. Some children have symptoms that last more than four weeks, and children have less long-term illness after SARS-CoV-2 infection than adults.
A UK study has for the first time detailed the COVID-19 illness among symptomatic children aged 5 to 17. The study included data from 1,734 children who tested positive at a similar time to when they developed symptoms of COVID-19, and who reported their symptoms regularly before they recovered.
Children with COVID-19 usually recover within a week with few symptoms (the course of the disease lasts an average of six days with an average of three symptoms), and the vast majority of symptomatic children recover within eight weeks (98.2%), which provides assurance for studying the long-term outcome of COVID-19. Despite this, some children (4.4%) had symptoms that lasted more than four weeks, and these children had an average of two persistent symptoms (usually fatigue, headache or loss of smell). Compared with adults, children with SARS-CoV-2 have less long-term disease.
Children’s symptoms are reported by parents or caregivers through the COVID Study app, developed by ZOE, and cannot be cross-checked against health records. The authors emphasize that all children with persistent symptoms need timely multidisciplinary care, combined with education, to promote their recovery.
A large UK study published recently in The Lancet Child & Adolescent Health confirmed that children with COVID-19 symptoms generally improved after six days, while The number of children with symptoms lasting more than four weeks was small (4.4%, 77/1,734). The study, based on data reported by parents and caregivers through a smartphone app, is the first to detail COVID-19 in school-age children with symptoms and provides evidence that children are less likely to develop long-term symptoms when they become ill.
Professor Emma Duncan, from King’s College London, UK, who was the study’s corresponding author, said: “It is reassuring that the number of children experiencing long-term symptoms of COVID-19 is small. However, a small number of children do show symptoms of COVID-19 disease over time, and our study confirms this.”
Some adults develop symptoms of long-term illness after being infected with COVID-19 (sometimes called “long-covid”) that last for four weeks or more, but it’s not known whether children experience similar conditions or how common they are. Many children infected with SARS-CoV-2 do not develop symptoms, but those who do tend to have mild symptoms.
For the new study, researchers used data collected through the COVID Research smartphone app developed by ZOE, which included data on more than 250,000 British children aged 5 to 17. Symptoms were reported by their parents or caregivers via the app (rather than directly assessing the children), and the team did not collect data on schooling.
The panel focused on reports collected between 1 September 2020 and 22 February 2021. About 1,734 children developed SYMPTOMS of COVID-19 at a time similar to their POSITIVE PCR test results, and they regularly reported their COVID-19 symptoms before recovering. This meant that researchers were able to accurately attribute these children’s symptoms to COVID-19 and were able to vigorously assess the duration of illness. Overall, these children were sick for an average of six days and had an average of three symptoms during the first week of illness, confirming that COVID-19 presents as a mild illness in children and that they usually recover quickly.
Most children recovered within four weeks, and a small number of children still had COVID-19 symptoms one month later (4.4%, 77/1,734). Typically, they had only two symptoms after four weeks. The most common symptom in children with a long course of illness is fatigue. Eighty-four per cent (65/77) of the children reported fatigue at some stage of the illness, which was the most persistent symptom. Headaches and loss of smell were also common (77.9%[60/79] of children experienced these during the course of the illness). However, headaches are more common in the early stages of the disease, while anosmelia tends to appear later and last longer.
Of 1,379 children who developed symptoms at least two months before the end of the study period (by 29 December 2020), fewer than 2% had symptoms lasting more than 8 weeks (1.8%, 25/1,379).
Older children were generally ill for longer than those of primary school age (an average of seven days for children aged 12 to 17, compared to five days for children aged 5 to 11). Older children were also more likely than younger children to still have COVID-19 symptoms four weeks later (5.1%[59/1,146] of children 12 to 17 years versus 3.1%[18/588] of children 5 to 11 years), However, there was no difference in the proportion of children who still had symptoms after 8 weeks (2%[19/934] of children aged 12 to 17 vs 1.3%[6/445] of children aged 5 to 11).
“We found that nearly a quarter of symptomatic children who tested positive for SARS-CoV-2 in the SECOND UK pandemic did not report core symptoms, suggesting that TESTING policies in the UK need to be reconsidered,” said Dr Erika Molteni, lead author of the study from King’s College London.
Importantly, the researchers also evaluated children who tested negative for COVID-19 and may have other childhood illnesses, such as colds and flu. For this work, they randomly selected a group of age – and sex-matched children, who also reported symptoms through the app, to be tested at the same time as children with positive results.
Children with COVID-19 were sick for longer (an average of six days for COVID-19 compared to an average of three days for other conditions) than children who tested negative for COVID-19 but had other conditions, They were more likely to be ill for more than four weeks (4.4%[77/1,734] in children with COVID-19 versus 0.9%[15/1,734] in children with other conditions). However, over the course of at least four weeks, the few children with other conditions tended to have more symptoms than those with COVID-19 (the COVID negative group averaged five symptoms, while the COVID positive group averaged two).
Dr Michael Absoud, consultant and senior lecturer at King’s College London and lead author of the study, said: “Our data highlights that other diseases, such as cold and flu, can also have long-term symptoms in children, which is important to consider when planning paediatric health services during and after the pandemic. This is especially important because the incidence of these diseases is likely to increase with the relaxation of physical quarantine measures put in place to prevent the spread of COVID-19. All children with persistent symptoms (from any illness) need timely, education-related multidisciplinary support to enable them to find their own path to recovery.”
The authors note that there are some limitations to their findings. They cross-checked symptoms reported by parents and caregivers against health records (noting that most children are managed in the community) and that there may be differences in the way parents interpret symptoms on behalf of their children. Crucially, only children whose parents participated in the STUDY on COVID-19 symptoms could participate, which could skew overall study participation in favor of certain populations.
They also noted that their findings on the number of children experiencing long-term symptoms were lower than the latest figures from the UK Government’s Office of National Statistics, ONS. The difference, the researchers suggest, could be because the two studies defined the end of COVID-19 disease differently. The current study also allowed children to relapse and relieve symptoms (allowing them to be completely healthy for a week). The difference between the data reported here and the ONS data is very similar when the ONS uses a similar cut-off point. In addition, the ONS estimates are based on data collected on a monthly basis, which relies on the details that individuals remember when they have symptoms, whereas the COVID symptom study collects data in real time.
Professor Emma Duncan added: “We hope our findings will be useful and timely for doctors, parents and schools looking after these children – and of course the infected children themselves.”