Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is typically very mild and often asymptomatic in children. A complication is the rare multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19, presenting 4-6 weeks after infection as high fever, organ dysfunction, and strongly elevated markers of inflammation. The pathogenesis is unclear but has overlapping features with Kawasaki disease suggestive of vasculitis and a likely autoimmune etiology.

Objectives: We report a case of multisystem inflammatory syndrome in children (MIS-C) in patient with SARS-CoV-2 infection and Enteropathogenic Escherichia coli (EPEC) sepsis due to acute enteritis, observed at end of December 2020 to a tertiary-care center (San Carlo Hospital), in Basilicata region (Italy).

Methods: This healthy 12-year- old male patient was tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Clinical presentations was characterized by fever, abdominal pain, gastrointestinal complaints and evanescent rash. Laboratory values were remarkable for high levels of procalcitonin, C-reactive protein (CRP), D-dimers, B-type natriuretic peptide (BNP), and troponin. He also had low albumin levels. Autoantibodies tests were negative. Chest tomography showed ground-glass opacities in less than 25% of the lungs, small bilateral pleural effusion and increased cardiac area; abdominal tomography showed enlargement of the lymphnodes and ascites. Evaluation for other infectious etiologies showed molecular test positivity on fecal samples for EPEC E. coli. He received broad spectrum intravenous antibiotics (macrolids and quinolones and then carbapenems). On the seventh day the enteritis resolved and procalcitonin normalized, however he continued to have lymphopenia, thrombocytopenia, hypoalbuminemia, elevated levels of CRP, D-dimers, ferritin, troponin, and increased BNP. On the ninth day he was feverish again and developed severe cardiac and respiratory failure requiring advanced respiratory support and admission to the intensive care unit. He received IVIG (intravenous immunoglobulin at 2 g/Kg, glucocorticoids (Methylprednisolone 1mg/kg) and enoxaparin.

Results: The patient was discharged asymptomatic at home after 28 days of hospital stay.

Conclusion: We observed multisystem inflammatory syndrome in children (MIS-C) in a previously healthy patient with SARS-CoV-2 infection and E.coli sepsis, who became critically ill with multisystem involvement. In this case viral and bacterial infections could be considered as a double hit for the etiopathogenesis of MIS-C. The trend of procalcitonin was better than C-reactive protein for differentiating bacterial from non-bacterial phase of systemic inflammatory response syndrome (SIRS) in this critically ill child. Although the accuracy of both tests is moderate. Diagnostic accuracy could be enhanced by combining these tests with bedside clinical judgment.

References: [1]Consiglio CR, Cotugno N, Sardh et al. The Immunology of Multisystem Inflammatory Syndrome in Children with COVID-19. Cell. 2020 Nov 12;183(4):968-981.e7. doi: 10.1016/j.cell.2020.09.016. Epub 2020 Sep 6. PMID: 32966765; PMCID: PMC7474869.

[2]Nakra NA, Blumberg DA, Herrera-Guerra A, Lakshminrusimha S. Multi-System Inflammatory Syndrome in Children (MIS-C) Following SARS-CoV-2 Infection: Review of Clinical Presentation, Hypothetical Pathogenesis, and Proposed Management. Children (Basel). 2020 Jul 1;7(7):69. doi: 10.3390/children7070069. PMID: 32630212; PMCID: PMC7401880.

[3]Simon L, Saint-Louis P, Amre DK, Lacroix J, Gauvin F. Procalcitonin and C-reactive protein as markers of bacterial infection in critically ill children at onset of systemic inflammatory response syndrome. Pediatr Crit Care Med. 2008 Jul;9(4):407-13. PMID: 18496408.

Disclosure of Interests: None declared