How infectious are children?
When do infected people have the highest viral load?
The virologist Christian Drosten published a study that caused a stir in 2020 in the specialist magazine "Science".
Berlin / Munich - Virologist Christian Drosten is proving to be one of the most highly regarded political advisors in the coronavirus pandemic.
His assessments of the situation have had weight and have been since the beginning of the crisis in early 2020, when he drew a conclusion from the first data from corona infected people about the risk of infection from children.
The result at the time: Children could be as contagious as adults.
In the debate about opening schools and kindergartens, Drosten's conclusion had received a lot of attention.
In addition, a violent dispute broke out between the virologist and the Bild newspaper.
The newspaper accused him of "questionable methods".
The virologist has now published his corona study in the well-known specialist magazine "Science".
According to a press release from the Charité, it is probably the largest study on this topic.
Does he stick to his assessment of the infectiousness of children?
Corona study by virologist Christian Drosten: more than 25,000 data included
How infectious are patients of different ages and symptom severity?
Virologist Drosten and a research team from Berlin Charité got to the bottom of these questions.
25,381 Covid-19 cases were included in the study.
Both infected people without signs of illness and patients with symptoms of varying severity up to hospital cases were taken into account.
The scientists around Christian Drosten determined the so-called viral loads for the more than 25,000 Covid-19 cases - "that is, the number of copies of the Sars-CoV-2 genome in the PCR sample," as explained in the press release.
"The copies of the genetic material approximately represent the amount of virus in the patient's throat and therefore allow predictions to be made about their potential infectiousness," explained the Charité.
Corona study by Drosten for Germany: "Equally high infectivity in all age groups"
"My initial impression that all age groups were almost equally infectious has been confirmed, not only here, but also in other studies," said Virologist Drosten in a press release from the Berlin Charité.
In the evening he affirmed in the
NDR podcast
: Based on the first data, a clinical virologist had seen that everyone had about the same amount of virus.
This impression has held up.
Central study results:
Adults:
The scientists found “no significant differences” in the viral load of those infected between the ages of 20 and 65.
Around 2.5 million copies of the Sars-CoV-2 genome were found.
Children:
"In the samples of the youngest children between the ages of zero and five, the research team found the lowest viral loads with around 800,000 copies of the genetic material," the statement said. "In older children and adolescents, the values matched those of adults with increasing age," says the averaging.
Virologist Drosten sees the values of children as influenced by a different way of taking samples compared to adults.
“With children, much smaller swabs are used, which bring less than half as much sample material into the PCR test.
In addition, instead of the painful deep nasopharynx swabs, simple throat swabs are often taken, in which there is even less virus, ”says Drosten.
For this reason, lower measured values are generally to be expected in children.
Drosten study on Corona: highest viral load one to three days before the onset of symptoms
In addition, the study supports the assumption that a relatively small proportion of those infected are responsible for a particularly high number of infections.
"Due to an extraordinarily high viral load", around nine percent of the Covid cases examined were noticed.
More than a third of them “had no or only mild symptoms”.
"The fact that there are so many people without relevant symptoms of the disease makes it clear why measures such as distance rule and the mask requirement are so important to control the pandemic," Drosten continued in the press release.
Infected people already have the highest viral load in the throat one to three days before the onset of symptoms, according to another result of the study.
It was also conspicuous: "The people who later become seriously ill have a lot of virus right from the start."
Another study finding relates to the British corona mutant B1.1.7.
People who are infected with the corona variant are apparently more contagious than those infected with other variants.
In comparison, their viral loads are increased by a factor of ten, according to Drosten.
That is considerable.
(mbr / dpa)
List of rubric lists: © Jens Schicke / imago
