Infection risk half in kids, but they spread coronavirus: Study
In a finding with implications for reopening schools, a new study has established that children and teenagers have half the risk of getting infected by Sars-Cov-2, the virus that causes Covid-19, as compared to adults.
However, the jury is out on whether children are less likely to spread the infection, according to a large systematic review of at least 6,300 studies, preprints and reports.
Children are 56% less likely than adults to get infected by Sars-Cov-2 when they come in contact with an infected person, but how easily they pass on the infection to others remains unclear, according to the study done by researchers at University College London, published in the preprint journal medRxiv.
The study hasn’t yet been peer reviewed.
“There is preliminary evidence that children and young people have lower susceptibility to Sars-CoV-2, with 56% lower odds of being an infected contact. There is weak evidence that children and young people play a lesser role in transmission of Sars-CoV-2 at a population level. Our study provides no information on the infectivity of children,” said the study, which analysed data from 6,327 studies published till May 16 this year.
The role of children and young people in spreading the disease depends on several factors, including their susceptibility to infection, severity of symptoms, viral load, social contact patterns and risk behaviour.
Clinical series and testing of symptomatic cases alone give biased estimates of susceptibility in children, who often don’t develop symptoms.
“The susceptibility of children to Sars-Cov2 is low, according to most of the information. If they are asymptomatic, as most are, transmission risk will be very low,” said K Srinath Reddy, president of the Public Health Foundation of India.
Studies on Covid-19 prevalence in children have produced widely varying results, the University College London analysis noted.
Large studies from Iceland, the Netherlands and Spain and Italy showed markedly lower Sars-CoV-2 prevalence among children and young people, but studies from Sweden, the UK and some cantons in Switzerland and Germany found no difference in infection prevalence between adults and children.
The Swedish Public Health Agency found 4.7% antibody prevalence in children and teenagers, compared to 6.7% in adults aged 20 to 64, and 2.7% in 65 to 70-year-olds, indicating significant spread in schools.
“Long-lasting school closures not only leads to a loss of learning but the isolation also harms their mental health and social development, so we have to consider whether the harm outweighs the infection risk for children, who can spread it to their families, school staff and the community,” said Rajesh Sagar, professor in the department of psychiatry at the All India Institute of Medical Sciences (AIIMS).
Most schools across India have been shut since March 21, the weekend before a national lockdown was announced by Prime Minister Narendra Modi on March 24.
Unlike Sweden, which kept day care centres and schools through ninth grade open without major adjustments to class size, lunch policies or recess rules, schools in India are unlikely to open before July to lower children’s expose to infection.
“Most young children find it difficult to follow social distancing norms and given the large number of students in one classroom, and crowded transport and playgrounds, schools can easily turn into infection clusters if children infect teachers or take the infection to their family and neighbourhood, even if they don’t get severe disease themselves,” said Sagar, who specialises in child mental health.
Socially and economically disadvantaged children, who depend on schools for mid-day meals, education, nutrition and health because of socioeconomic disadvantages, are among the worst hit by prolonged school closure.
A paper on rethinking the role of schools after Covid-19, published in The Lancet, stated: “School provides a structured setting in which children can learn and develop social competencies, such as self-confidence, friendship, empathy, participation, respect, gratitude, compassion, and responsibility. Social and emotional learning is important for young people to become conscious members of a solidarity-based community.”
A hybrid model of education with greater dependence on e-learning is being used in many countries that are reopening schools post lockdown, but it has its challenges. “Since all children do not have access to online learning because of uneven access, teaching using radio and television should be considered as that group cannot be ignored,” Sagar said.