Severe multisystem inflammatory syndrome (MIS-C/A) after confirmed SARS-CoV-2 infection: a report of four adult cases.

BACKGROUND: Multisystem inflammatory syndrome (MIS) triggered by a recent SARS-Cov-2 infection has been recognised worldwide. Although predominantly affecting children (MIS-C), similar presentations have been reported among adults (MIS-A). METHOD: A retrospective case series describing four critically ill patients with MIS-C/A diagnosed between January and April 2021 at Sahlgrenska University Hospital, Gothenburg, Sweden. Clinical presentation, laboratory and radiological findings, treatment and outcome are reported. RESULTS: Cases occurred in previously healthy patients with a history of laboratory-confirmed mild SARS-CoV-2 infection four to seven weeks earlier. The median age was 24 years (range 19-43) and 3/4 were male. All fulfilled suggested MIS-C/A criteria according to the US Centre for Disease Control and all required care at an intensive care unit. Treatment was initiated with intravenous immunoglobulin, interleukin-1-receptor antagonists, and pulse steroids in 3/4 cases which resulted in rapid clinical improvement. No severe complications were noticed in any case during a three-month follow-up period. CONCLUSION: MIS-C/A should be considered, irrespective of age, in patients with fever, hyperinflammation and multiple organ system involvements emerging weeks after COVID-19. Previously suggested treatment regimens for MIS-C seem to be applicable also for MIS-A.

Exponential distance statistics to detect the effects of population subdivision.

Statistical tests are needed to determine whether spatial structure has had a significant effect on the genetic differentiation of subpopulations. Here we introduce a new family of statistics based on a sum of an exponential function of the distances between individuals, which can be used with any genetic distance (e.g., nucleotide differences, number of nonshared alleles, or separation on a phylogenetic tree). The power of the tests to detect genetic differentiation in Wright-Fisher island models and stepping stone models was calculated for various sample sizes, rates of migration and mutation, and definitions of spatial neighborhoods. We found that our new test was in some cases more powerful than the Ks* statistic of Hudson et al. (Mol. Biol. Evol. 9, 138-151, 1992), but in all cases was slightly less powerful than both a traditional chi2 test without lumping of rare haplotypes and the S(nn) test of Hudson (Genetics 155, 2011-2014, 2000). However, when we applied our new tests to three data sets, we found in some cases highly significant results that were missed by the other tests.