Today there are two studies describing the new findings of multiple system inflammatory syndrome (MIS-C) and the unique but similar Kawasaki disease (KD) associated with COVID-19 in children.
Low blood pressure, shock, cardiac dysfunction
In the first study, published in Jama Pediatrics, Led by the US Centers for Disease Control and Prevention (CDC) researchers team used laboratory data comparing the geographic and temporal distribution of MIS-C March 2020 to January 2021 and COVID-19 distributed over the same period.
In the largest MIS-C patient cohort and its distribution in the United States, the cumulative incidence rate is 2.1
Among the 1,733 MIS-C patients, 90.4% involved at least four organ systems, 54% had hypotension or shock, 58.2% required intensive care, and 31.0% had abnormal cardiac function. Pericardial effusion (accumulation of sac fluid around the heart) accounted for 23.4%, myocarditis (myocarditis) accounted for 17.3%, coronary artery dilation or aneurysm (blood vessel wall expansion) accounted for 16.5%.
Patients aged 18 to 20 have the most severe symptoms and signs of MIS-C, of which 30.9% suffer from myocarditis, 36.4% suffer from pneumonia, and 18.2% suffer from acute respiratory distress syndrome (ARDS). This age group is most likely to have reported a previous coronavirus-like illness (63%). In contrast, children aged 0 to 4 years have the fewest signs and symptoms of severe MIS-C, but 38.4% suffer from hypotension or shock, while 44.3% require intensive care.
53% to 67% of MIS-C patients have gastrointestinal symptoms, rashes, and conjunctival hyperemia (eye inflammation). Other common symptoms include fever, vomiting, skin rash and diarrhea. Among all MIS-C patients, boys accounted for 57.6%, Hispanics or blacks accounted for 71.3%, and the median age was 9 years.
Delayed immune response to coronavirus
The countries with the heaviest MIS-C burden are usually in the West and Midwest. The first two peaks of MIS-C nationwide occurred 2 to 5 weeks after the surge in COVID-19 and the spread of the virus from urban to rural areas.
According to the authors, most cases of MIS-C occur after asymptomatic or mild COVID-19 infection, and the excessive inflammation occurs at the same time as the highest antibody production several weeks later.
They wrote: “The geographic and temporal link between MIS-C and the COVID-19 pandemic indicates that MIS-C is due to a delayed immune response to SARS-CoV-2 infection.” “Clinical manifestations vary with age and prior COVID-19. The presence or absence of change.”
Researchers are calling for the development of laboratory markers or diagnostic tests to distinguish MIS-C from severe COVID-19 and other inflammatory diseases such as Kawasaki disease. They concluded: “Physicians should remain highly susceptible to MIS-C in order to quickly diagnose and treat these patients.”
In a review in the same issue of the journal, Dr. Jennifer Blumenthal and Jeffrey Burns, MD, MPH, both Boston Children’s Hospital, said that the results of the study showed a lack of prior coronavirus symptoms especially young children, should not discourage MIS-C did not affect their heart pediatrician.
“If all pediatric populations in the world are at risk of COVID-19, and compared with adults, the vaccination of pediatric populations will be delayed, then this potentially serious consequence must be placed on the pediatricians around the world. The forefront of differential diagnosis, pending further results research,” they wrote.
Kawasaki disease may spread through the air
Published on JAMA network is openThe second study was led by researchers at Fukuoka Children’s Hospital in Japan to determine the role of droplets in contact with KD. This longitudinal study covered 1,649 KD patients and 15,586 infectious disease patients who were hospitalized in six centers from 2015 to 2020.
KD is an acute disease that mainly affects children between 6 months and 5 years of age (the median age of the KD cohort is 25 months), and has the characteristics of small and medium vascular inflammation. Although the cause of KD is unknown, it is believed to occur after exposure to environmental triggers (such as infection) in children with genetic predispositions.
Researchers found that from April to May, 2015 to 2019, compared with the same period in 2020, the number of hospitalizations for KD did not change significantly (the average number of hospitalizations per month was 24.8 vs 18.0; a decrease of 27.4%; the adjusted incidence rate [aIRR], 0.73).
However, at the same time, the number of hospitalizations for respiratory infections spread by droplets or contact dropped from an average of 157.6 cases per month to 39.0 cases, a decrease of 75.3% (aIRR, 0.25), and the hospitalization rate for gastrointestinal infections (43.8 to 6.0) The number of hospital admissions per month) decreased by 86.3% (aIRR, 0.14), and infections decreased by 12,254.
As a result, by April 2020 and May 2020, the ratio of KD to respiratory and gastrointestinal infections transmitted through droplets or contact has increased significantly (ratio 0.40 to 0.12).
“These findings indicate that transmission through contact or droplets is not the main way for KD to occur in Japan, and supports the results of previous epidemiological studies, indicating that KD may be related to airborne diseases in most cases. More extensive research is necessary Learn more about this fascinating disease,” the author wrote.