Whole-genome sequencing confirms Shigella flexneri infection in a child with shock and suspected Multisystem Inflammatory Syndrome in Children: A case report

A previously healthy 6-year-old boy acutely presented with fever, vomiting, diarrhea, fluid-refractory shock, cardiac dysfunction, biochemical inflammation, and coagulopathy. He fulfilled diagnostic criteria for multisystem inflammatory syndrome in children. He received both antibiotics and pulsed intravenous methylprednisolone, with rapid improvement. Stool molecular testing revealed Shigella flexneri infection, confirmed by culture, mass spectroscopy and whole-genome sequencing. Serologic testing confirmed prior infection by the SARS-CoV-2 virus. The child fully recovered. Immunological investigations were normal.