A new study by a Canadian public health
agency has revealed that babies and toddlers are less likely to bring the novel
coronavirus into their homes than teenagers are, but once they are infected,
they are more likely to spread the virus to others in their households.

The findings explain that, at least in parts, by behavioural
factors, including the fact that very young children require lots of hands-on
care and cannot be isolated when they are sick.

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The study, published in the journal JAMA Pediatrics on
Monday, does not resolve an ongoing debate over whether infected children are
as contagious as adults, and it does not suggest that toddlers are driving the
pandemic.

Zoe Hyde, a public health researcher at the University of
Western Australia, said, “This study showed that even the youngest of children
readily transmit the virus.”

“The key takeaway for me is that it clearly shows that
there’s transmission from children occurring in the household. This means we
urgently need to think about how we’re going to protect schools when they
reopen shortly,” she further added.

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During the initial stage of COVID-19 pandemic, scientists
suggested that young children rarely got infected by the virus. But those
observations may have been distorted by the fact that most children had few
social encounters during that time.

“I think they were biased by the fact that children were
sequestered at home,” said Dr Tina V Hartert, a respiratory researcher at
Vanderbilt University, who was not involved in the new study. “They were
recommended not even to play with neighbours, they didn’t go to school, they
didn’t go to day care.”

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The ‘Index case’

The new study is based on records of COVID-19 cases and
positive coronavirus tests in Ontario from June 1 to December 31, 2020. The
researchers identified all positive tests associated with private households
and then identified the “index case” in each household.

They focused on as many as 6,280 households in which the
first person to catch COVID-19 was under 18. They later looked for secondary
cases, or others in the same home who got sick in the two weeks after the first
child fell ill.

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In most cases, they found, the chain of transmission stopped
with the infected child, but in 27.3% of households, children passed the virus
along to at least one other resident.

Adolescents were most likely to bring the deadly virus into
the home. Children ages 14-17 made up 38 per cent of all the index cases.
Children ages 3 or younger were the first to get sick in just 12 per cent of
households.

The findings may be the result of behavioural differences
between toddlers and teenagers, medical experts said.

What are the chances of disease transmission in children?

According to the study, it is also possible that the
youngest children may carry higher levels of the deadly virus, or have higher
rates of viral shedding, than teenagers. Some studies have found that even
though young children rarely get severely ill, they may carry similar levels of
virus than adults do.

Schools and day cares can also help prevent children from
getting infected in the first place by taking a variety of precautions,
including physical distancing and good ventilation when children are old enough
for it.