Multisystem Inflammatory Syndrome in Infants <12 months of Age, United States, May 2020–January 2021

Abstract

Background: Multisystem inflammatory syndrome in children (MIS-C), temporally associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been identified in infants <12 months old. Clinical characteristics and follow-up data of MIS-C in infants have not been well described. We sought to describe the clinical course, laboratory findings, therapeutics and outcomes among infants diagnosed with MIS-C. Methods: Infants of age <12 months with MIS-C were identified by reports to the CDC's MIS-C national surveillance system. Data were obtained on clinical signs and symptoms, complications, treatment, laboratory and imaging findings, and diagnostic SARS-CoV-2 testing. Jurisdictions that reported 2 or more infants were approached to participate in evaluation of outcomes of MIS-C. Results: Eighty-five infants with MIS-C were identified and 83 (97.6%) tested positive for SARS-CoV-2 infection; median age was 7.7 months. Rash (62.4%), diarrhea (55.3%) and vomiting (55.3%) were the most common signs and symptoms reported. Other clinical findings included hypotension (21.2%), pneumonia (21.2%) and coronary artery dilatation or aneurysm (13.9%). Laboratory abnormalities included elevated C-reactive protein, ferritin, d-dimer and fibrinogen. Twenty-three infants had follow-up data; 3 of the 14 patients who received a follow-up echocardiogram had cardiac abnormalities during or after hospitalization. Nine infants had elevated inflammatory markers up to 98 days postdischarge. One infant (1.2%) died after experiencing multisystem organ failure secondary to MIS-C. Conclusions: Infants appear to have a milder course of MIS-C than older children with resolution of their illness after hospital discharge. The full clinical picture of MIS-C across the pediatric age spectrum is evolving.

Multisystem Inflammatory Syndrome in Children: Follow-Up of a Cohort from North India

“…The majority of studies reporting long-term follow-up of children with MIS-C are from developed countries, 10 – 16 and there is lack of such data from the Indian subcontinent. In this retrospective study from North India, we described the follow-up of 34 children with MIS-C who were admitted during the first wave of SARS-CoV-2 infection and demonstrated that majority of the children were asymptomatic and myocardial dysfunction and coronary artery changes resolved in majority during follow-up.…”

“…Information on the long-term outcome of MIS-C is limited to a few studies from developed countries. 10 – 16 Therefore, we planned this follow-up study to describe the clinical features, echocardiographic findings, and long-term outcome of children with MIS-C from a tertiary care center in North India.…”

Infants hospitalized for acute COVID-19: disease severity in a multicenter cohort study

“…CRP is a sensitive marker of inflammation even in neonates [ 8 , 9 ] so we hypothesize a lower level of measurable inflammation in infants compared to older children admitted with COVID-19, but it may reflect admission of infants with milder disease. Less inflammation might partially explain why infants accounted for only 4% of MIS-C cases in a large series [ 10 ].…”

Long-Term Complications of COVID-19 Infection in Adolescents and Children

“…The signs and symptoms of MIS-C include fever, abdominal pain, vomiting, diarrhea, skin rash, mucocutaneous lesions, hypotension, and cardiovascular and neurologic compromise [ 33 ]. Reviews of complications secondary to MIS-C have been described elsewhere [ 34 , 35 ].…”