Covid-19: possible link between the virus and Kawasaki disease

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Hospitalizations of children with Kawasaki disease jumped 497% two weeks after the Covid-19 epidemic peak in April in France, suggesting a fairly clear link between the virus and the development of the disease.

Doctors wondered about the possible link between exposure to the new coronavirus and the growing prevalence of a multisystemic inflammatory syndrome affecting the heart and digestive system of children, similar to Kawasaki disease.

According to a study carried out by the general pediatrics department at Robert-Debré hospital in Paris, hospitalizations of children with Kawasaki disease jumped 497% two weeks after the peak of the Covid-19 epidemic in April , while the hospital had only identified 230 cases between 2005 and 2020, or about fifteen cases per year on average, which also puts into perspective the scope of the very strong increase observed. “This link appears quite clearly”, confirmed Monday July 20 Professor Albert Faye, head of the general pediatrics department at Robert-Debré hospital in Paris.

To compare the annual prevalence of this disease, doctors sought to identify other respiratory viruses circulating at the time: “During the period of containment, they collapsed. Clearly, SARS-CoV-2, the agent of Covid-19, was the only one circulating at that time”. The only one, therefore, to be able to be at the origin of these hundreds of cases.

A more severe form but which can be treated

Occurring mainly in children under 5 years old, Kawasaki disease causes inflammation of the walls of the blood vessels which can lead to serious cardiac sequelae, and in some cases even death. It is characterized by high fever, rash, swelling of the glands in the neck, irritation and/or redness of the whites of the eyes (bilateral conjunctivitis), irritation/inflammation of the mouth, tongue, lips and throat and swelling of the hands and feet.

However, when it is caused by the new coronavirus, it becomes “more severe” with “an attack on the digestive level, abdominal pain”. The inflammation is “a little bit more important than in the classic disease”, since it affects the heart muscle.

Nevertheless, the treatment remains effective. Although this complication remains rare, prevention remains essential: “Like any viral infection, we must remain vigilant. We don’t know everything ”. Concretely, a child with Kawasaki disease “is a very tired child who has a prolonged fever (4 or 5 days of fever), digestive disorders and a skin rash”. The manifestation of these symptoms “should lead to a consultation”, insists the pediatrician.

The role of genetics

This multisystem inflammatory syndrome does not seem to affect all children in the same way. Indeed, doctors have noticed an ethnic over-representation among these young patients, suggesting that children with African origins would be more at risk.

A study recently published in JAMA found that 38% of a sample of 58 children with this syndrome had African origins and only 12% had Caucasian origins. Same observation at Necker Hospital: 12 of the 21 hospitalized children (57%) were of sub-Saharan African origin. In short, the intensity of this syndrome could have a link with genetic factors in children, but it is still difficult to explain this trend with certainty. Several hypotheses have been put forward, but none is unanimous.