CORONAVIRUS

Spanish study finds only 8% of children with coronavirus transmitted it to their family

Researchers from the Vall d’Hebron hospital say these results explain why there have not been more outbreaks in schools in Spain

A mother waiting for her child’s PCR test results.
A mother waiting for her child’s PCR test results.CATI CLADERA / EFE

A new study by the Vall d’Hebron hospital in Barcelona has found that only 8% of pediatric patients with confirmed coronavirus in Catalonia transmitted the virus to a member of their family. The study, titled Pediatric Covid in Catalonia: Uniting efforts to respond to Covid-19, was carried out between July 1 and October 31 on 1,081 pediatric patients with a positive PCR test and 3,515 family contacts that were diagnosed with the coronavirus in that period. The study, which is set to be published shortly, also found that 47% of the children who tested positive for the coronavirus (a total of 506) were asymptomatic.

The first results of the investigation were presented in August using data from the period between March 1 and May 31, when Spain was under a strict lockdown, with schools closed and tight restrictions on movement. In this stage, researchers found that 3.4% of pediatric patients with coronavirus transmitted the virus to their family unit. The new data covers the summer period and the first seven weeks following the reopening of schools, when the country entered the so-called “new normality,” meaning children had a lot more social contact. In this period, as soon as a child was diagnosed with coronavirus, their pediatrician began tracking their contacts – something that did not happen in the first stage.

Now we can see that the free movement of children and the return to schools have not led to a greater transmission of the virus
Pere Soler, pediatrician at Vall d’Hebron hospital

“The later study confirms that children transmit the virus less than adults in the household, as the first part of the research had indicated,” explained Pere Soler, the head of the pediatrician unit of infectious and immuno-deficient diseases at Vall d’Hebron hospital. “Now we can see that the free movement of children and the return to school has not led to a greater transmission of the virus,” he added.

In the second part of the study, in 783 of the cases (72.4%), another member of the family clearly had coronavirus symptoms before the child. Only in 86 cases (8%) was it determined after contact tracing that the pediatric patient had transmitted the virus to other members of their family. However, in another 55 cases (5%), the child had caught the virus from another minor in the family.

According to the investigation, 53% of pediatric patients presented symptoms, with the most common being fever (70.6%, 406 cases), followed by coughing (36.9%, 212 cases), headaches (24.5%, 141 cases), fatigue (24.3%, 140 cases) and diarrhea (16.3%, 94 cases). “The number of children who need to be admitted into hospital continues to be very low [2.5%],” said Antoni Soriano, from the pediatric unit of infectious and immuno-deficient diseases at Vall d’Hebron hospital. Of the pediatric patients who were hospitalized between March and May, 99.2% (1,006 cases) recovered completely, while 0.4% (five cases) suffered after-effects. No deaths were recorded in this period.

“The impact of Covid-19 on children in Catalonia continued to be very minor after the confinement period, with children freely moving about,” said Magda Campins, the head of preventive medicine and epidemiology at Vall d’Hebron hospital. “In more than 70% of cases, the infection has been spread by an adult.”

“In the last few months, the number of PCR tests being carried out has increased exponentially, also among children. We have gone from 36,400 in August to 79,140 in September and more than 140,000 in October,” said Juliana Esperalba, of the microbiology department at Vall d’Hebron hospital and the co-leader of the PCR and serology testing program included in the study. During the first eight weeks since schools in Spain reopened, 287,046 PCR tests have been carried out on children across the country.

English version by Melissa Kitson.


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