Since the start of the epidemic, children are very little affected by the virus and the forms observed are mostly benign. Deaths only occur in less than 1% of cases, confirms a European study published in the specialist journal The Lancet Child & Adolescent Health. Of the 582 patients studied who tested positive for the virological test (RT-PCR), only four died, all over the age of 10, two of whom suffered from pre-existing medical problems.
The return to school initially worried parents and education unions, who feared a restart of the epidemic, in particular because children have less control over barrier gestures. In addition, it was not known what role they could play in the circulation and transmission of the virus. The fear being that they are important “silent” vectors, so that they transmit the disease more easily than adults, including in the absence of symptoms. In reality, a study conducted by pediatricians in Ile de France showed that children are not very contaminating. Another study by the Institut Pasteur, the results of which are published on June 23, goes in the same direction.
On a scientific level, what do we know today about the behavior of SARS-CoV-2 on children?
1 – Children are not very contaminating, a “certainty”
At the start of the epidemic, it seemed certain that Covid-19 was mainly carried and transmitted by children, even if they were not sick or symptomatic. This was also what had motivated the closure of schools. Today, with more hindsight, we realize that children are less “carriers” than adults.
According to a study carried out by the Institut Pasteur in the primary schools of Crépy-en-Valois (Oise), where the coronavirus circulated massively at the start of the epidemic, transmission is low between young children. Of the 510 students from six primary schools included in the study, there were three probable cases of SARS-CoV-2 infection in three different schools before the schools closed for the February school holidays and then for the confinement in Crépy-en-Valois. These cases did not give rise to secondary cases, either among other schoolchildren or among teaching staff, the study reports. In addition, the proportion of infection is very high (61%) among parents of infected children, while it is only 6.9% among parents of uninfected children. “This suggests that the parents were the source of the infection of their children in many cases”, summarizes the Institut Pasteur.
“Overall, the results of this study are comparable to those of other studies carried out abroad, which suggest that children aged 6 to 11 become infected more in the family environment than at school. The main new information provided by this study is that infected children did not transmit the virus to other children, teachers or other school personnel.However, these results need to be confirmed in other studies given the low number of introductions of the virus into schools that have been studied”, comments Arnaud Fontanet, first author of the study, head of the Epidemiology of Emerging Diseases Unit at the Institut Pasteur.
These reassuring results thus confirm another study conducted by Professor Robert Cohen, pediatrician in Créteil (Val-de-Marne) and vice-president of the French Society of Pediatrics. According to this study, children (up to the age of 15) are very little contagious. In an interview with Parisian, this June 4, the pediatrician affirms it: we know with “certainty” that children are not “super-contaminators”, quite the contrary. “We now know that they are very small contaminators. At the start of the crisis, we believed – as for other respiratory viruses – that they played an important role in the spread of the epidemic. not the case.”
The French Society of Pediatrics is based on a study it conducted (from April 14 to May 12) with 600 children between 3 months and 18 years old, in the Paris region. All were tested by PCR and fingertip blood test (serological test). Result serological tests show that 10% of children in Ile-de-France, the most affected region, have been infected with the coronavirus. Additionally, 1.8% had a positive PCR test when screened during lockdown. But, emphasizes Dr. Cohen, “we were really surprised to see that only 0.6% were contagious.”
Another argument put forward by the pediatrician: less than one in ten clusters has a child as its starting point.
Finally, a study carried out in Contamines-Montjoie and published in the journal Clinical infectious diseases also came to this conclusion. She had studied the case of the 9-year-old child, who although infected with Covid-19 had continued to attend three schools and a ski club before the health alert was given. The study concluded that none of the 172 people with whom the child had been in contact had been infected with the virus, not even the other two children of his siblings. This suggests that “children may not be an important source of transmission of this new virus” and suggests “a different transmission dynamic in children.
Why are they less contaminating? Several hypotheses are put forward:
- The children would have fewer SARS-CoV-2 receptors on their nasal mucosa.
- Children could be better protected by their cross-immunity. What is it about ? Children, it’s not a scoop, get sicker than adults, they are very exposed to colds and other viruses. However, the cold virus belongs to the family of coronaviruses. Children would thus be more protected by this immune memory.
- L’trained immunity could also play: since they are sick more often, children would simply be more resistant to infections.
2 – Children fall less ill and when they do, they are benign forms
One thing also seems certain: if there is danger, it does not primarily concern schoolchildren. The studies all point in the same direction: the Covid-19 affects children little.
According to a European study, deaths related to Covid-19 in children are extremely rare and occur in less than 1% of cases. Experts from Great Britain, Austria and Spain found that, in children, the disease remained mainly benign. The results of the study have been published in The Lancet Child & Adolescent Health end of June 2020.
According to a detailed analysis of hospitalizations and deaths due to COVID-19 in Francepublished on April 21 by the Pasteur Institute, while 8.3% of people over 80 affected by the virus died, this figure drops to 0.001% among those under 20 years old.
According to a Chinese study, published in the Journal of the American Medical Association (JAMA) At the end of February 2020, among the more than 70,000 cases of coronavirus recorded in China, there are “only” 2% of children and adolescents under the age of 19. The researchers add that no deaths of children under the age of 9 have occurred. According to this large study, severe cases are observed mainly in the elderly and with comorbidities.
As of March 23, of the nearly 58,000 Italian cases, only 597 were children and adolescents under the age of 18 (1%), the hospitalization rate for children was 11% (17.5% among those under 1 year and 7% for those over 7 years old). None of the children required intensive care (data from the Istituto Superiore di Sanità).
French data confirm the mildness of the infection in children (serious cases and deaths are extremely rare). Children under 15 represent less than 1% of intensive care admissions in France. One death occurred in a 16-year-old girl (French public health data). Another case (10 years old) was announced on April 9, but Jérôme Salomon, the director general of health, specified that he had “significant comorbidities”.
3 – In children, as in adults, non-specific symptoms
The Institut Pasteur study carried out in Crépy-en-Valois also confirms that most often young children, when infected with this new coronavirus, do not develop symptoms of the disease or present minor symptoms which can not lead to evoke the diagnosis. The very characteristic signs of loss of taste and loss of smell were never observed in children under 15 in this study, whereas they were reported by half of the adults”. adds Bruno Hoen, last author of the study and director of medical research at the Institut Pasteur.
In a study published on February 14, 2020 in the Journal of the American Medical Association (JAMA), researchers analyze the clinical picture of 9 children under 1 year old affected by Covid-19 in China between December 8 and February 2.
Results ? “Scientists evoke a viral infection”paucisymptomatic“- that is, with very mild symptoms.
The French Society of Pediatrics notes that “clinical signs in adults and children are non-specific”. Clearly, we can observe one symptom or the other, several at the same time, or none. In addition, “almost all the cases of children reported are secondary cases, within the framework of a family contamination, the disease of adults preceding those of children.”
Barrier gestures in children and adolescents:
The French Society of Pediatrics (SFP) also recalls the “barrier gestures” which limit the spread of the virus and prevent contamination, both outside and at home: wash your hands very regularly (with hydroalcoholic gel during outings , with soap at home), cough or sneeze into your elbow, use single-use tissues when blowing your nose. The mask is only compulsory in schools for middle school students. In public transport, wearing a mask is compulsory from the age of 11.
Source:
French Society of Pediatrics (SPF)
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