Given the strong geographical and temporal relationship between SARS-CoV-2 infections and subsequent PIMS-TS risk, we postulated that it would be possible to predict, through modelling, the number of PIMS-TS cases in subsequent COVID-19 waves. Subsequently it was noted that PIMS-TS and Kawasaki Disease had distinct characteristics and likely represented different syndromes ( 1, 15, 16).

In the United States, where PIMS-TS is termed multisystem inflammatory syndrome in children (MIS-C) ( 1, 13), the risk of PIMS-TS during the first wave of the pandemic (April to June 2020) was estimated to be 5.1 persons per million person-months or 316 persons per million SARS-CoV-2 infections in 0–20 year-olds ( 14). In May 2020, an observational cohort study of children in Italy estimated a thirty-fold increase in the incidence of Kawasaki-like Disease during the first wave of the SARS-CoV-2 pandemic ( 6). During the first pandemic wave in England, both the size and timing of the peak of PIMS-TS incidence were associated with SARS-CoV-2 infection, regionally and nationally ( 10). In response to increasing number of cases nationally, Public Health England (PHE), now known as the UK Health Security Agency (UKHSA), rapidly initiated prospective enhanced national surveillance of PIMS-TS through the British Paediatric Surveillance Unit ( 10).Īlthough the precise causal mechanisms underpinning the relationship between SARS-CoV-2 and PIMS-TS is not established, we and others have previously reported a strong temporal link between the two ( 10– 12). The first reports of KD-/TSS-like presentations coincided with the first pandemic wave, initially in London, UK ( 3), but soon reported across England ( 5), and globally in countries and regions experiencing a COVID-19 pandemic wave ( 6– 9). Endemic cases of SARS-CoV-2 increased exponentially from mid-March, reaching a peak in mid-April 2020, and then declining gradually until the end of May 2020 ( 4). In England, the first imported cases of SARS-CoV-2 were identified in January 2020. PIMS-TS shares clinical features of Kawasaki Disease (KD) and Toxic Shock Syndrome (TSS) and is characterised by single-organ or multi-organ dysfunction, with a high rate of myocardial dysfunction with cardiogenic shock, severe gastrointestinal involvement, including hyperinflammation and even subsequent transient aneurysms of the coronary arteries ( 2, 3). Paediatric Multisystem Inflammatory Syndrome (PIMS-TS) is a rare life-threatening complication that typically occurs around two to six weeks after SARS-CoV-2 infection in children and young people (CYP) ( 1, 2).

Alpha Class by T.S. Paul