CDC Updated MIS-C Cases - March 2021

 

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Although children are often thought of as usually only mildly affected by COVID-19, almost a year ago, in PICS: NHS Alert On Possible Severe Pediatric COVID-19 Complication, we saw the first alert from the UK of a life-threatening Kawasaki-like syndrome in children linked to COVID infection.

A week later the CDC would issue their first alert (see CDC HAN: Multisystem Inflammatory Syndrome In Children (MIS-C)), which was followed up with a CDC COCA Call : Multisystem Inflammatory Syndrome in Children (MIS-C) four days later. 

Since then, this syndrome has been identified in thousands of children around the world - and while the numbers remain small - surveillance and reporting continue to lag.

The CDC describes the syndrome on their MIS-C website as:

 

What is MIS-C?

Multisystem inflammatory syndrome in children (MIS-C) is a condition where different body parts can become inflamed, including the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal organs. Children with MIS-C may have a fever and various symptoms, including abdominal (gut) pain, vomiting, diarrhea, neck pain, rash, bloodshot eyes, or feeling extra tired. We do not yet know what causes MIS-C. However, many children with MIS-C had the virus that causes COVID-19, or had been around someone with COVID-19.

Can adults get MIS-C?

Since June 2020, several case reports and series have reported a similar multisystem inflammatory syndrome in adults (MIS-A). Learn more.

While relatively rare, MIS-C can be life threatening, and so the CDC offers the following advice.  

In the first five months (Apr-Sept) of reporting, fewer than 1,000 cases were reported in the United States (see MMWR: COVID-19–Associated Multisystem Inflammatory Syndrome in Children — U.S., March–July 2020).  In early October, 2020 the CDC reported the nation's case count had exceeded 1,000 cases and 20 related deaths. 

That number doubled between October 1st and February 1st, with the CDC reporting 2060 cases and 30 related deaths on Feb 8th.

Over the past 30 days, the CDC has confirmed nearly 600 additional cases (see below), and there are more under investigation. As our understanding of how to identify and treat cases has grown, the fatality rate has fallen, but three more fatalities were reported last month. 

Some excerpts from the March 4th CDC Update follow:

Summary

• Most cases were in children and adolescents between the ages of 1 and 14 years, with a median age of 9 years.
• Cases have occurred in children and adolescents from <1 year old to 20 years old.
• 66% of reported cases have occurred in children who are Hispanic or Latino (842 cases) or Black, Non-Hispanic (746 cases).
• 99% of cases (2,591) tested positive for SARS CoV-2, the virus that causes COVID-19. The remaining 1% were around someone with COVID-19.
• More than half (59%) of reported cases were male.

MIS-C Cases by Jurisdiction

Since reporting began in mid-May, 48 states, New York City, Puerto Rico, and Washington, DC, have reported at least one case of MIS-C to CDC. Because of the small number of cases in some states and to protect the privacy of patients and their families, CDC is not reporting individual states’ case counts.

Race and Ethnicity of Reported MIS-C Cases

In addition to location of MIS-C cases, CDC is closely monitoring characteristics of MIS-C patients by race and ethnicity and age. To date, the majority of MIS-C patients have been Hispanic/Latino and Non-Hispanic Black. Hispanic/Latino and Non-Hispanic Black populations are also disproportionately affected by COVID-19 overall. Additional studies into MIS-C are needed to learn why certain racial or ethnic groups may be affected in greater numbers and what risk factors may contribute to this phenomenon.

Next steps

Children and adolescents appeared to be less likely than adults to be infected or to have severe illness early in the COVID-19 pandemic and may have asymptomatic or mildly symptomatic COVID-19. However, as the outbreak has progressed, larger numbers of children and adolescents are getting infected. CDC and state partners will be monitoring for additional cases and will adapt MIS-C recommendations as needed.

CDC investigators are assessing reported cases and children and adolescent’s health outcomes to try to learn more about specific risk factors for MIS-C, progression of the illness in children and adolescents, and how to better identify MIS-C and distinguish it from similar illnesses.

(Continue . . . )

For more on what we know about MIS-C, both in children and in adults, you may wish to revisit some of these earlier blogs:

MMWR: Multisystem Inflammatory Syndrome in Adults (MIS-A) Associated With SARS-CoV-2 Infection

CHOP Research: COVID-linked MIS-C Associated with Myocardial Injury

J. Peds: Pediatric SARS-CoV-2: Clinical Presentation, Infectivity, and Immune Responses