A single-center experience from Eastern India depicting the epidemiology and phenotypic variations of Multisystem inflammatory syndrome in children (MISC) associated with SARS-CoV2 seen after first wave and second wave of COVID 19

Introduction: Multisystem inflammatory syndrome in children (MIS-C) associated with SARS-CoV-2 caused significant health concerns worldwide. In our center, we had encountered the first wave of MIS-C from June 2020 to January 2021, whereas the second wave surged up from April 2021 to August 2021. In this study, we have done a comparative analysis of different phenotypes of MIS-C seen during these two waves. Subjects and Methods: This was a single-center observational study where the children fulfilled the WHO criteria for MIS-C were included in the study. Clinical and laboratory findings, course of the illness, treatment, and outcome were noted down, and the patients were followed up. Depending on the presentations, cases were classified in four different phenotypes (Type 1: MIS-C overlapping with acute COVID-19, Type 2: MIS-C with shock/MIS-C with multiple organ dysfunction syndrome (MODS), Type 3: MIS-C Kawasaki disease phenotype, Type 4: Mild MIS-C/Febrile inflammatory state), and a comparative analysis of these phenotypes in the two waves was done. Results: There were 86 cases in 7 months during the first wave, whereas 102 cases in 5-month duration during the second wave. The clinical manifestations and laboratory findings were compared, type 2 phenotypes increased in proportion requiring more pediatric intensive care unit admissions. Mortality was seen during the 2nd wave which was absent in our cohort during the first wave. Conclusions: MIS-C typically showed a spectrum of disease manifestations starting from a mild febrile inflammatory state to full-blown MODS. Early phenotypic differentiation and targeted immunomodulatory therapy depending on the phenotype had shown to be useful.