New York: New research suggests that children can shed SARS-CoV-2, the virus that causes Covid-19, even if they never develop symptoms or for long after symptoms have cleared.

The study, published in the journal JAMA Pediatrics, provides important insight on the role children might play in the spread of Covid-19 as communities continue to develop public health strategies to reign in this disease.

The study that sparked this commentary focused on 91 pediatric patients followed at 22 hospitals throughout South Korea. “Unlike in the American health system, those who test positive for Covid-19 in South Korea stay at the hospital until they clear their infections even if they aren’t symptomatic,” said study researcher Roberta L. DeBiasi from Children’s National Hospital in the US.

The patients here were identified for testing through contact tracing or developing symptoms. About 22 per cent never developed symptoms, 20 per cent were initially asymptomatic but developed symptoms later, and 58 per cent were symptomatic at their initial test.

Over the course of the study, the hospitals where these children stayed continued to test them every three days on average, providing a picture of how long viral shedding continues over time.

The study’s findings show that the duration of symptoms varied widely, from three days to nearly three weeks. There was also a significant study in how long children continued to shed virus and could be potentially infectious.

While the virus was detectable for an average of about two-and-a-half weeks in the entire group, a significant portion of the children — about a fifth of the asymptomatic patients and about half of the symptomatic ones — were still shedding virus at the three-week mark.

The researchers wrote that the study makes several important points that add to the knowledge base about Covid-19 in children.

One of these is a large number of asymptomatic patients — about a fifth of the group followed in this study. Another is that children, a group widely thought to develop a mostly mild disease that quickly passes, can retain symptoms for weeks.

A third and important point, they said, is the duration of viral shedding. Even asymptomatic children continued to shed virus for a long time after initial testing, making them potential key vectors.

Recently, a study published in The BMJ journal, revealed that children and young people have less severe Covid-19 than adults and death is exceptionally rare.

Earlier, another research published this month in the Journal of Pediatrics, found that children play a larger role in the community spread of the Covid-19.