Clinical characteristics of children and young people admitted to hospital with covid-19 in United Kingdom: prospective multicentre observational cohort study
Authors: Swann Olivia V , Holden Karl A , Turtle Lance , Pollock Louisa , Fairfield Cameron J , Drake Thomas M , Seth Sohan , Egan Conor , Hardwick Hayley E , Halpin Sophie , Girvan Michelle , Donohue Chloe , Pritchard Mark , Patel Latifa B , Ladhani Shamez , Sigfrid Louise , Sinha Ian P , Olliaro Piero L , Nguyen-Van-Tam Jonathan S , Horby Peter W , Merson Laura , Carson Gail , Dunning Jake , Openshaw Peter J M , Baillie J Kenneth , Harrison Ewen M , Docherty Annemarie B , Semple Malcolm G 
Published: August 2020

Abstract

Objective
To characterise the clinical features of children and young people admitted to hospital with laboratory confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the UK and explore factors associated with admission to critical care, mortality, and development of multisystem inflammatory syndrome in children and adolescents temporarily related to coronavirus disease 2019 (covid-19) (MIS-C).

Design
Prospective observational cohort study with rapid data gathering and near real time analysis.

Setting
260 hospitals in England, Wales, and Scotland between 17 January and 3 July 2020, with a minimum follow-up time of two weeks (to 17 July 2020).

Participants
651 children and young people aged less than 19 years admitted to 138 hospitals and enrolled into the International Severe Acute Respiratory and emergency Infections Consortium (ISARIC) WHO Clinical Characterisation Protocol UK study with laboratory confirmed SARS-CoV-2.

Main outcome measures
Admission to critical care (high dependency or intensive care), in-hospital mortality, or meeting the WHO preliminary case definition for MIS-C.

Results

Median age was 4.6 (interquartile range 0.3-13.7) years, 35% (225/651) were under 12 months old, and 56% (367/650) were male. 57% (330/576) were white, 12% (67/576) South Asian, and 10% (56/576) black. 42% (276/651) had at least one recorded comorbidity. A systemic mucocutaneous-enteric cluster of symptoms was identified, which encompassed the symptoms for the WHO MIS-C criteria. 18% (116/632) of children were admitted to critical care. On multivariable analysis, this was associated with age under 1 month (odds ratio 3.21, 95% confidence interval 1.36 to 7.66; P=0.008), age 10-14 years (3.23, 1.55 to 6.99; P=0.002), and black ethnicity (2.82, 1.41 to 5.57; P=0.003). Six (1%) of 627 patients died in hospital, all of whom had profound comorbidity. 11% (52/456) met the WHO MIS-C criteria, with the first patient developing symptoms in mid-March. Children meeting MIS-C criteria were older (median age 10.7 (8.3-14.1)
v
1.6 (0.2-12.9) years; P<0.001) and more likely to be of non-white ethnicity (64% (29/45)
v
42% (148/355); P=0.004). Children with MIS-C were five times more likely to be admitted to critical care (73% (38/52)
v
15% (62/404); P<0.001). In addition to the WHO criteria, children with MIS-C were more likely to present with fatigue (51% (24/47)
v
28% (86/302); P=0.004), headache (34% (16/47)
v
10% (26/263); P<0.001), myalgia (34% (15/44)
v
8% (21/270); P<0.001), sore throat (30% (14/47)
v
(12% (34/284); P=0.003), and lymphadenopathy (20% (9/46)
v
3% (10/318); P<0.001) and to have a platelet count of less than 150 × 10
9
/L (32% (16/50)
v
11% (38/348); P<0.001) than children who did not have MIS-C. No deaths occurred in the MIS-C group.

Conclusions
Children and young people have less severe acute covid-19 than adults. A systemic mucocutaneous-enteric symptom cluster was also identified in acute cases that shares features with MIS-C. This study provides additional evidence for refining the WHO MIS-C preliminary case definition. Children meeting the MIS-C criteria have different demographic and clinical features depending on whether they have acute SARS-CoV-2 infection (polymerase chain reaction positive) or are post-acute (antibody positive).

Study registration
ISRCTN66726260.