Paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PIMS-TS): Prospective, national surveillance, United Kingdom and Ireland, 2020

Abstract

Background: Paediatric Multisystem Inflammatory Syndrome temporally associated with SARS-CoV-2 (PIMS-TS), first identified in April 2020, shares features of both Kawasaki disease (KD) and toxic shock syndrome (TSS). The surveillance describes the epidemiology and clinical characteristics of PIMS-TS in the United Kingdom and Ireland.

Methods: Public Health England initiated prospective national surveillance of PIMS-TS through the British Paediatric Surveillance Unit. Paediatricians were contacted monthly to report PIMS-TS, KD and TSS cases electronically and complete a detailed clinical questionnaire. Cases with symptom onset between 01 March and 15 June 2020 were included.

Findings: There were 216 cases with features of PIMS-TS alone, 13 with features of both PIMS-TS and KD, 28 with features of PIMS-TS and TSS and 11 with features of PIMS-TS, KD and TSS, with differences in age, ethnicity, clinical presentation and disease severity between the phenotypic groups. There was a strong geographical and temporal association between SARS-CoV-2 infection rates and PIMS-TS cases. Of those tested, 14.8% (39/264) children had a positive SARS-CoV-2 RT-PCR, and 63.6% (75/118) were positive for SARS-CoV-2 antibodies. In total 44·0% (118/268) required intensive care, which was more common in cases with a TSS phenotype. Three of five children with cardiac arrest had TSS phenotype. Three children (1·1%) died.

Interpretation: The strong association between SARS-CoV-2 infection and PIMS-TS emphasises the importance of maintaining low community infection rates to reduce the risk of this rare but severe complication in children and adolescents. Close follow-up will be important to monitor long-term complications in children with PIMS-TS.

Funding: PHE.

Fig. 1a

(a) Diagram showing cases submitted to BPSU through to those used in the final analysis. (b) Venn diagram showing overlap of PIMS-TS/Kawasaki/TSS case definitions.

Fig. 2a

A map of all BPSU reports of PIMS-TS cases in England with postcode information (n = 246), alongside the rate of COVID-19 cases in LTLAs in England up to the 1st of July.

Fig. 2b

Confirmed COVID-19 cases by PHECs alongside PIMS-TS cases by week of onset. Note different y-axes used. Left axes for confirmed COVID-19 cases, right axes for PIMS-TS cases.

Fig. 2c

(c) Confirmed COVID-19 cases in England alongside PIMS-TS cases by week of onset. Note different y-axes used. Left axes for confirmed COVID-19 cases, right axes for PIMS-TS cases. (d) Graphical representation of the latent class model identified from the PIMS-TS data. The red bars represent the conditional probability, by class, that a case will have a given organ system involvement or a positive PCR/serological test. The proportion of total cases falling into each class are given at the bottom of the figure. Bars l-R represent: Class 1, Class 2, Class 3.