An interesting research letter in the Journal of the American Medical Association by Radtke and others on July 15th 2021 explored this issue.
Children can experience SARS-CoV-2 post-viral syndromes, but it is unclear to what extent these individuals are affected by long COVID.
Evidence is predominantly limited to select populations without control groups, which does not allow estimating overall prevalence and burden in the general paediatric population.
This study compared symptoms compatible with long COVID in children and adolescents hereafter called children reported within six months after SARS-CoV-2 serological testing.
The study investigated SARS-CoV-2 seroprevalence in 55 randomly selected schools in the canton of Zurich in Switzerland.
They were selected randomly from 12 districts with a number of schools proportional to population size. They invited all children of randomly selected classes to participate and between June 2020 and April 2021 three testing phases included collection of venous blood for serological analysis and online questionnaires for symptoms.
They compared children who had tested positive for SARS-CoV-2 antibodies in October or November 2020 with those who tested negative. They excluded children who were seronegative in October or November and seroconverted or not retested by March or April 2021.
In March to May 2021, parents recorded symptoms of their children occurring since October 2020 and lasted for at least four weeks, as well as whether the symptoms persisted for more than 12 weeks.
Overall, 1355 of 2503 children, 54%, median age 11 years and 54% girls with a serology result in October/November 2020 were included.
Of these 238 children were not eligible because they seroconverted.
292 were not retested and 618 because they did not provide information on symptoms.
Compared with the children not included, those included in the analysis were younger median age 11 versus 12 years and more likely to be girls, 54% versus 49% and their parents had a higher proportion of university or college education, 77% versus 64%.
Age and sex distribution was comparable between the seropositive children and the seronegative children.
Between October and November 2020 and March and April 2021, 4 of 109 seropositive children, 4%, versus 28 of 1246 seronegative ones, 2%, reported at least one symptom lasting beyond 12 weeks.
The most frequently reported symptom lasting more than 12 weeks among seropositive children was:
- Tiredness: 3 out of 109 (3%)
- Difficulty in concentrating: 2 out of 109 (2%)
- Increased need for sleep: 2 out of 109 (2%).
None of the seropositive children reported hospitalisation after October 2020.
Similar proportions of seropositive and seronegative children reported excellent or good health.
This study found a low prevalence of symptoms compatible with long COVID in a randomly selected cohort of children assessed 6 months after serological testing.
Although long COVID exists in children, estimates of the prevalence of persisting symptoms is based on scarce literature range from 0%-27%.
Initial SARS-CoV-2 infection severity, different methodological approaches clinical assessment versus self-reporting, definition of cases diagnosed versus suspected, variable follow-up times and prevalence of pre-existing clinical conditions contributes to the variability in prevalence estimates.
This study reported the distribution of symptoms compatible with long COVID on a population level. It did not capture severe CoV-2 infections because they were rare in children.
A strength of this study is the population-based seronegative control group.
Limitations include the relatively small number of seropositive children, lack of information on the exact time of SARS-CoV-2 infection and possible misclassification of some children with false seropositive results.
However, it does appear to show that there are few children who suffer long COVID symptoms.
The London General Practice, the leading London doctors’ clinic in Harley Street offers full support for all long COVID sufferers.
They have brought together a multidisciplinary team to manage and review all aspects of long COVID. If you have any concerns or symptoms, please do not hesitate to get in touch.
Dr Paul Ettlinger
BM, DRCOG, FRCGP, FRIPH, DOccMed