What factors predispose children to developing a severe form of COVID-19? Canadian, Costa Rican and Iranian researchers conducted a study that shed light on some underlying health issues that increase risk.
The study involved 403 children who had been hospitalized between the start of the pandemic and May 31, 2021 for the sole reason that they suffered from COVID-19, which disease had been confirmed by a PCR test performed on respiratory secretions.
The researchers wanted to know what were the particular factors and characteristics of children who developed a serious infection, that is, who died or needed respiratory support, such as a high flow of oxygen administered. under pressure or intubation combined with mechanical ventilation, or who have required hemodynamic treatment aimed at maintaining a good heart rate and normal blood pressure.
The results of this study, which were obtained from data from 16 Canadian pediatric centers, as well as a children’s hospital in Costa Rica and another from the Iranian University of Medical Sciences, in Tehran, were reported public this week on the MedRxiv preprints site, but they have yet to be peer reviewed.
The researchers noted that “the age of the children as such was not a factor associated with the severity of the infection,” even though older children, especially adolescents, were more likely to be infected. develop a severe form of COVID-19. But this higher incidence of severe cases among hospitalized adolescents “was largely due to the fact that more of them had underlying chronic illnesses. This comorbidity seemed more important than age in predicting whether a child was at risk for a more severe form of COVID-19, ”said the study’s lead author, Dr.r Jesse Papenburg, pediatric microbiology and infectious disease specialist at the Montreal Children’s Hospital.
Obesity and neurological diseases
Analysis of the data showed that children who had two or more underlying illnesses were, because of their frailty, more likely to develop a serious infection. Among these health problems already present, obesity has emerged as “the most important risk factor in adolescents”, while it is “neurological diseases, such as global neuromuscular disorders, which are more complex problems than migraine, which made young children under the age of 12 “more at risk of developing a particularly serious infection.
The researchers also found that anemia and hemoglobinopathies, such as sickle cell anemia in which the shape of red blood cells is abnormal, were also associated with more severe COVID-19.
“Identifying these characteristics that were present in children before their hospitalization and which seem to predispose them to more severe COVID-19 will surely help Public Health to set up a more targeted vaccination program and to focus its efforts to increase the vaccination rate in populations with these characteristics, ”notes Dr.r Papenburg.
In addition, “we have found clinical signs that could alert the clinicians who take care of these patients in the hospital and which would warn them that patients who present these characteristics are more at risk of seeing their condition deteriorate, and that they need to be watched more closely, ”says Dr.r Papenburg.
Inflammatory syndrome
Thus, the researchers observed that young patients were more seriously ill if they already suffered from another viral (rhinovirus, adenovirus) or bacterial (pneumococcal) infection than COVID-19, if the imaging of their lungs looked like that of a person with COVID-19, if they were having difficulty breathing, if their blood levels of neutrophils (a type of white blood cell involved in the inflammatory reaction) were higher than normal, or if they developed a multisystem inflammatory syndrome.
Multisystem inflammatory syndrome typically occurs four to eight weeks after contracting COVID-19, which may have been low in symptoms or even asymptomatic, recalls Dr.r Papenburg. Given this delay, it was initially believed to be Kawasaki disease, which is also an inflammatory syndrome triggered by a viral infection. But it was then realized that the inflammatory syndrome associated with COVID-19 had certain differences: the ages of the children who developed it were different, the arteries of the heart were less affected than in Kawasaki disease. During this post-infectious response, the immune system that has been stimulated by the COVID-19 infection triggers an inflammatory response that is normally well under control, but which for some reason gets carried away, gets out of control and can cause in children a high fever, as well as skin, gastrointestinal, heart, kidney and liver problems. A third of affected children need to stay in intensive care, but we can fortunately treat them effectively with anti-inflammatory drugs, ”explains the specialist, who also participated in a study specifically on this syndrome.
In the latter study, 22% of 232 children with multisystem inflammatory syndrome included in the analysis had other underlying conditions. Children aged 6 to 12 appeared to be the most at risk for requiring referral to intensive care. The researchers also noted that ICU admissions to Canadian hospitals increased significantly during the period from November 2020 to March 2021, compared to the previous period, particularly between March and May 2020. “It is possible that differences in the immune response to circulating variants compared to that induced by the original virus alter the severity of the infection and the multisystem inflammatory syndrome ”, suggest the authors of the article to explain this increase in the number of cases requiring intensive care.