Can children spread the new coronavirus? The science still isn’t clear

The new coronavirus has mostly spared children, making them represent only a tiny fraction of confirmed Covid-19 cases, while largely affecting the elderly and those with pre-existing chronic conditions and weakened immune systems.

According to research, less than 2% of reported infections in China, Italy and the US have been in people under the age of 18. In South Africa, out of a total 312 deaths (recorded on 19 May), none occurred in anyone under the age of 20. Yet, researchers are still on the fence on whether children are less likely than adults to get infected and spread the virus, notes an article in the research journal Nature

Children and Covid-19

The World Health Organization (WHO) previously reported that although children seem to be mildly affected with no fatalities, experts still warn that children can contract the virus, and that this warrants serious consideration. The reason behind mild cases in children is not exactly clear, but experts agree that adults may be more susceptible to infection because of their age, since, with age, our immune systems become less effective.

A study, published in Science last month, examined data from Hunan and found that for every infected child under 15 years, there were close to three people infected between the ages of 20 and 64. Still, the existing data is less conclusive when it comes to teenagers aged 15 and older, says Munro, further indicating that their risk of infection is similar to that of adults.

Although there aren’t many studies looking at the transmission of the virus from schools to the broader community, an Australian report suggests that the transmission is limited, and particularly lower than other respiratory viruses, such as influenza.

A meta-analysis led by Kirsty Short, a virologist at the University of Queensland in Brisbane, Australia, examined several household studies and found that children are unlikely to bring the infection into a home, although Gary Wong, a researcher in paediatric respiratory medicine at the Chinese University of Hong Kong argued that the research is biased, explains Nature.

However, according to a previous Health24 article, another study, published in the Journal of Public Health Management and Practice, suggests that the virus is hitting younger children harder than we thought. And a study published in The Lancet Infectious Diseases last month, which analysed households with confirmed Covid-19 cases in Shenzhen found that children under the age of ten face the same risk of infection as adults, but that they are simply less likely to display severe symptoms, suggesting that they could be silent carriers of the virus and still spread it among the population. 

Does existing data support reopening of schools?

Alasdair Munro, a paediatric infectious-diseases researcher at University Hospital Southampton, UK told Nature that he believes that current evidence is sufficient to support the reopening of schools. In Germany, older children started returning to school earlier this month. But many parents disputed this decision, and ultimately won the right to keep their children at home, the Telegraph reported. In France and Australia, students are also set to return gradually over the following weeks.

South Africa’s basic education minister Angie Motshekga also announced the department’s plans for a phased resumption of schooling yesterday, stating that all schools would reopen on June 1, although this would be limited to grades seven and 12. However, schools with small student bodies will have the option of opening their doors for all grades, News24 reported.

On the flipside, there are scientists who, like many parents, disagree with the rushed reopening of classrooms and argue that it could only fuel a resurgence in infections. Another significant factor they highlight is that since Covid-19 is less severe in children, it is adults who are mostly receiving testing. So, if children are in fact "silent" carriers of the virus, as a preprint study in March suggested, we could see a spike in cases in the next few weeks – something our healthcare system may not be prepared for.

“I do not see any strong biological or epidemiological reason to believe that children don’t get as infected,” Wong explained to Nature.

“As long as there is community transmission in the adult population, reopening of schools will likely facilitate transmission, as respiratory viruses are known to circulate in schools and day cares.” Wong suggests that if schools are to reopen, reliable surveillance and testing systems should be in place prior to children returning to classrooms. In her media briefing, Motshekga mentioned that children will be screened daily.

READ | Coronavirus in SA: All the confirmed cases

READ | Are immune-compromised kids at greater risk from Covid-19?

READ | Dogs may catch coronavirus from owners, but won't infect humans

Image: Getty/Alex Grimm

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