A large study reviewed hospital cases to assess the pattern of COVID-19 symptoms in children and what factors lead to a higher risk of severe illness.
Initial studies of the COVID-19 pandemic show that, unlike with other respiratory viruses, children and young people seem to have a lower risk of infection with the SARS-CoV-2 virus than adults. Children make up only around 1-2% of COVID-19 cases worldwide and the majority of these cases are mild or asymptomatic. However, a very small number of children develop more severe illness and may need critical care support. Pediatricians have also identified small clusters of children who developed a condition known as multisystem inflammatory syndrome (MIS-C) following SARS-CoV-2 infection. Children with MIS-C may develop a rash, very low blood pressure, heart dysfunction, blood clotting disorders, and gastrointestinal problems.
As part of a wider study looking at the clinical characteristics of COVID-19 patients, researchers in the United Kingdom analyzed COVID-19 symptoms in children hospitalized with SARS-CoV-2 infection. They looked for factors which increase the risk of needing intensive care support, mortality, or the development of MIS-C. The study findings were recently published in the BMJ.
COVID-19 symptoms in children milder than in adults
The study was part of the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) WHO Clinical Characterization Protocol (CCP-UK), a global collaborative study looking at various aspects of COVID-19. The researchers analyzed data from 651 children (<19 years old) admitted to 138 hospitals across the UK, with confirmed SARS-CoV-2 infection. They studied the clinical characteristics of the children and the risk factors for admission to critical care, in-hospital mortality, and the development of MIS-C.
Overall, the children made up less than 1% of the hospital admissions in the ISARIC CCP-UK study. The average age of the children in hospital was 4.6 years. Forty-two percent of the children had at least one other medical condition – most commonly neurological conditions or asthma. There was a low mortality rate, with six deaths – all in children who had other significant health issues. Eighteen percent of the children hospitalized required critical care treatment. Age <1 month, age between 10-14 years, black ethnicity and obesity were risk factors for critical care admission.
A total of 52 children developed MIS-C, and these children were five times more likely to need intensive care. Apart from the MIS-C symptoms identified in earlier reports, this study found that headaches, tiredness, muscle aches and sore throat were also linked to MIS-C. In addition, children with MIS-C had low platelet counts (a blood component involved in clotting).
Results of study should reassure parents as children return to school
The researchers concluded that children and young people have less severe COVID-19 than adults. “We want to highlight that children made up only a fraction of a percent of all COVID-19 admissions across the UK in our study and that severe disease was rare,” commented Dr. Olivia Swann, University of Edinburgh, co-lead author of the study. The researchers hope their results will reassure parents, particularly as children begin to return to school – although it is important to continue monitoring COVID-19 in children.
While the overall risk of COVID-19 for young people is lower, as with adults, obesity and black ethnicity are risk factors for more severe disease. The researchers want to understand more about the reasons for this and why a small number of children develop the inflammatory syndrome MIS-C following SARS-CoV-2 infection. The additional symptoms and low platelet counts noted in MIS-C cases in this study may help to identify future cases.
Prof. Calum Semple, University of Liverpool, co-lead author added, “This report is the largest and most detailed description of COVID-19 and MIS-C in children and young people. We have provided new understanding about MIS-C which will help manage this rare but serious condition.”
Written by Julie McShane, MA MB BS
1. Swann OV, Holden KA, Turtle L, et al. Clinical characteristics of children and young people admitted to hospital with covid-19 in United Kingdom: prospective multicenter observational cohort study. BMJ 2020;370:m3249 doi: https://doi.org/10.1136/bmj.m3249
2. University of Edinburgh, Press release 27 Aug 2020. COVID-19 less deadly and causes milder symptoms in children. https://www.eurekalert.org/pub_releases/2020-08/uoe-cld082620.php
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