Table 1.

Case definitions of COVID-19 and MIS-C

WHO case definitions of COVID-19
Suspect case	Acute respiratory illness AND a history of travel or residence in a location with community transmission or contact with a confirmed or probable case of COVID-19 in the last 14 days prior to symptoms OR exposure to confirmed or probable COVID-19 case in 14 days prior to symptoms onset OR Severe acute respiratory illness requiring hospitalization in the absence of alternative diagnosis
Probable case	A suspect case with inconclusive COVID-19 testing or if testing could not be performed for any reason
Confirmed case	Patient with laboratory confirmation of COVID-19 irrespective of clinical signs or symptoms
Illness severity	Mild/moderate No new or increased supplemental oxygen requirement Severe New or increased supplemental oxygen requirement without needing new or increased non-invasive/invasive mechanical ventilation Critical New or increased non-invasive/invasive mechanical ventilation requirement OR presence of sepsis or multi-organ failure or rapidly worsening clinical trajectory
Case definitions of MIS-C
CDC definition	Age < 21 years presenting with fever (38 °C for at least 24 h), laboratory evidence of inflammation and evidence of clinically severe illness requiring hospitalization with multisystem (> 2) organ involvement (cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic or neurological) with no alternative plausible diagnoses AND Positive for current or recent SARS-CoV-2 infection (RT-PCR, serology or antigen test) or COVID-19 exposure within 4 weeks prior to symptoms onset
WHO definition	Age 0–19 years with fever > 3 days AND at least two of the following: (i) Rash or bilateral non-purulent conjunctivitis or mucocutaneous inflammation (ii) Hypotension or shock (iii) Features of myocardial dysfunction, pericarditis, valvulitis, or coronary abnormalities (echo findings, elevated troponin/BNP) (iv) Evidence of coagulopathy (prolonged PT or PTT, elevated D-Dimer) (v) Acute gastrointestinal problems (diarrhea, vomiting, or abdominal pain) AND Elevated markers of inflammation (ESR, CRP, Procalcitonin) with no other obvious microbial cause of inflammation AND Evidence of COVID-19 (RT-PCR, antigen test or serology positive), or likely contact with patients with COVID-19

COVID-19 coronavirus disease 2019, MIS-C/PMIS multisystem inflammatory syndrome in children/pediatric multisystem inflammatory syndrome, RT-PCR reverse transcription polymerase chain reaction, SARS-CoV-2 severe acute respiratory syndrome coronavirus