Most children with a severe inflammatory disease related to the coronavirus had initial Covid-19 infections with no symptoms or only mild symptoms, new US research shows.
The unusual post-infection condition tends to be milder in children who were sickest with Covid-19, although more than half of the affected youth received intensive hospital care, according to an analysis by the Centers for Control and Prevention of Federal Diseases published Tuesday in JAMA Pediatrics. .
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The study represents the largest analysis to date of US cases of multisystem inflammatory syndrome in children and reinforces the evidence that it is a delayed immune response to Covid-19. The study included nearly 1,800 cases reported to the CDC from March 2020 through mid-January. Most were children under the age of 15, but the study included up to 20 years.
The increases in cases have occurred two to five weeks after the Covid-19 spikes and have followed the spread of initial infections from urban to rural areas, the researchers said. The most recent data from the CDC indicates that there is another emerging peak in pediatric condition consistent with that trend.
Cases reported by the state as of March 29 totaled 3,185 and included 36 deaths, the CDC website shows. State reports are not always timely, so it is not known how many American children developed the disease since the study ended.
Most of the children who had Covid-19 do not develop the disease after infection. Nearly 3.5 million American children and adolescents have tested positive for Covid-19, according to data compiled by the American Academy of Pediatrics and the Association of Children’s Hospitals.
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The condition was first reported in Europe in late winter and spring last year. Some cases, especially those that follow silent and undiagnosed Covid-19 infections, can be mistaken for Kawasaki disease, a rare condition that can cause skin redness, swelling, and heart problems.
Dr. Sean O’Leary, vice chair of the committee on infectious diseases at the academy of pediatrics, said the inflammatory condition usually makes children sick very quickly, but most “respond very well to treatment and the vast majority improve. completely”.
Treatments may include steroids and other medications that can reduce inflammation.
The best way to prevent it is to prevent Covid-19 infections, “for which vaccines are very good,” he said. Studies of the Covid-19 vaccine in children are underway.
In the CDC analysis, fever was among the most common symptoms. At least half of the affected children had abdominal pain, vomiting, diarrhea, and a red skin rash. Almost a third had inflammation of the heart or other heart involvement. These symptoms were less common among children up to 4 years old, who were also less likely to require intensive care than older children.
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