Public schools are reopening in NYC, though COVID-19 is still spreading, with new businesses flat out around 3,500 a day nationwide, and more infectious variants starting to take hold.
Children are much less likely to catch the virus, but some who do can experience serious consequences in the form of Multisystem Inflammatory Syndrome in Children, or MIS-C. It is a condition in which various body organs become inflamed, including the heart, lungs, brain and skin.
Now, a study by Northwell Health, the state’s largest health system, shows a worrying outcome for COVID-positive children and their kidneys. The researchers reviewed the medical records of 152 pediatric patients with COVID-19, which were recorded from March to August at four hospitals in the New York area. About one in ten children with COVID-19 had acute kidney injuries. The share doubled for those who also developed MIS-C. Severe renal function in children is usually very rare – in the order of one to two dozen cases per 100,000 children in developed countries.
Dr. Christine Sethna is an associate professor at Northwell’s Feinstein Institutes for Medical Research and one of the co-authors of the study. She spoke to David Furst of WNYC about their findings, how parents can spot MIS-C and when children are eligible for COVID-19 vaccines. The interview was lightly edited for clarity.
Can you briefly describe to us how MIS-C works? How long does it take to appear after a child catches COVID? And how does it affect the body?
We do not know the exact reason or mechanism, exactly how it occurs. But we know it’s a post-viral syndrome, which means we believe it’s related to a previous COVID infection. It usually occurs six to eight weeks after infection.
What did your study find in terms of MIS-C and kidney injury? How often do you see it?
Therefore, we studied the incidence of acute renal injury, which is defined as the sudden cessation of renal function. And we looked at 152 children admitted to our four hospitals in the Northwell Health system, with both the acute COVID-19 infection and MIS-C. And in the total group, we found that 11.2% had this acute kidney injury. Specifically, of the 55 children with the MIS-C, the incidence was slightly higher; it was about 18.2%.
In general, children admitted to hospital with COVID and MIS-C are very rare, and in addition, it is still rare to develop kidney injury. But we want to let the public and the medical profession know that this is a complication of COVID.
Fortunately, most children who had acute kidney injury did resolve. We did have a couple who needed dialysis to help the kidney remove the waste from the body. But the majority did decide. Only two children left the hospital with more kidney problems.
The CDC says New York City and New York State have reported between 150 and 250 cases of MIS-C in childhood. How worried should parents be?
In general, however, COVID-19 infection occurs much lower in children compared to adults. And from the relationship with COVID infection, the rate of MIS-C is even rarer. So there are more than 2000 cases nationwide. It is therefore extremely rare, but parents should still be aware of it.
Daily MIS-C cases and COVID-19 cases in American children (seven-day moving average), 19 February 2020 and 21 February 2021.
Age of reported MIS-C cases in the United States as of March 1, 2021
CDC
Race / Ethnicity of reported MIS-C cases in the United States from March 1, 2021
CDC
What should parents look out for?
About six to eight weeks after a known COVID infection, they should seek medical attention if they have signs of vomiting, diarrhea, high fever, skin symptoms, or lethargy.
What’s the latest on the COVID-19 vaccine trials in children? How long before they can get the vaccine and before they are vaccinated in large numbers?
Right. The Pfizer vaccine is therefore already approved for ages 16 and older, but it is not yet available from the state to get the vaccine unless you currently have a medical condition. But if it opens, the Pfizer vaccine could be eligible for 16 and older.
Both Pfizer and Moderna completed their clinical trials for children aged 12 to 15 years and up to 18 for Moderna. And so we probably expect these results in late spring, early summer.
At best, I would say summer for the 12 to 15 age group until late fall. The next phase is the children under the age of 12. They have not yet started participating in the group. So it will be much later, probably late in the year or even early in 2022.