MIS-C: Cases of rare inflammatory syndrome linked to COVID-19 on the rise among children in US

Cases of a rare inflammatory syndrome linked to COVID-19 have been on the rise across the country amid the ongoing coronavirus pandemic, according to the U.S. Centers for Disease Control and Prevention. 

In August, The CDC reported that nearly 600 children had been hospitalized in the United States with multisystem inflammatory syndrome in children, or MIS-C.

MIS-C is a condition that causes various parts of the human body to become inflamed, including the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal organs, according to the CDC. 

The CDC says the number of MIS-C cases in the U.S. surpassed 1,000 as of Oct. 1, 2020. As of Feb. 1, the number had surpassed 2,000.

MIS-C cases have now been reported in 48 states, New York City, Puerto Rico and Washington, D.C.

Most cases have been identified in children and adolescents between the ages of 1 and 14 years, while 69% of reported cases have occurred in children who are Hispanic or Latino, according to the health agency. 

Ninety-nine percent of all identified cases were in children who had tested positive for COVID-19. 

Dr. Jean Ballweg, medical director of pediatric heart transplant and advanced heart failure at Children’s Hospital & Medical Center in Omaha, Nebraska, told the New York Times that the hospital was only treating about two cases of MIS-C cases per month from April through October last year.

Ballweg said the number of monthly cases rose to 10 in December and January with 60% requiring intensive care. 

The CDC says MIS-C is a new syndrome and questions still remain as to why children and adolescents develop the illness after contracting COVID-19. 

The CDC said that the inflammatory condition was first reported in the United Kingdom as early as late April. On May 12 last year, New York City Mayor Bill de Blasio said 100 children in the city had been diagnosed for MIS-C. Of the 100, 55 tested positive for COVID-19 or had antibodies indicating a previous infection.

Medical experts had initially thought the syndrome could be linked to Kawasaki disease, another rare childhood condition that can cause swelling and heart problems, because the symptoms of the two conditions are similar. 

More than a year into the pandemic, researchers are still stumped by an array of ever-evolving symptoms and long-term effects that appear in coronavirus patients. 

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A study published on June 25, 2020, in the journal Cell Reports Medicine found that while COVID-19 is commonly known as a respiratory illness, the disease has also been known to instigate inflammatory responses in the body which can negatively affect the function of one’s heart and brain.

According to the study, researchers observed SARS-CoV-2 infecting human heart cells that were grown from stem cells in a lab. Within 72 hours of infection, the virus managed to spread and replicate, killing the heart cells. 

Another study published last month in the medical journal The Lancet found that some of the first people to be hospitalized for COVID-19 experienced symptoms lasting for up to six months. 

Researchers looked at 1,722 coronavirus patients who had been discharged from Jin Yin-tan hospital in Wuhan, China, where the disease was first identified.

The patients were discharged from the hospital between January 7, 2020, and May 29, 2020, and were then interviewed about their symptoms and quality of life pertaining to their health. They were also administered physical examinations and blood tests, as well as a six-minute walking test.

RELATED: COVID-19 symptoms remained for at least 6 months for some Wuhan patients, study finds

Approximately three-quarters of the patients still reported symptoms within six months after contracting the deadly virus.

More than 60% reported still experiencing fatigue or muscle weakness, while 23% reported anxiety and depression.
"At six months after acute infection, COVID-19 survivors were mainly troubled with fatigue or muscle weakness, sleep difficulties, and anxiety or depression," study authors write. "Patients who were more severely ill during their hospital stay had more severe impaired pulmonary diffusion capacities and abnormal chest imaging manifestations, and are the main target population for intervention of long-term recovery."