In the national conversation about the reopening of schools, this has been a comforting prohibition: young children are mostly spared by coronoviruses and do not seem to spread it to others, at least not very often.
But on Thursday, a study introduced an unwanted wrinkle in this spontaneous narrative.
According to research, the nose and throat of infected children have at least as many coronoviruses as infected adults. In fact, children under 5 can host 100 times as much of the virus in the upper respiratory tract as adults, the authors found.
This measurement does not necessarily prove that children are giving the virus to others. Nevertheless, the findings should influence the debate over the reopening of schools, many experts said.
“The school’s situation is so complex – there are many nuances beyond just the scientific one,” Dr. Taylor Heald-Sergeant, Ann and Robert H. of Chicago A pediatric infectious disease specialist at Lurie Children’s Hospital, who led the study. Published in JAMA Pediatrics.
“But one way out of this is that we cannot assume that children are not sick, or very ill, because they do not have the virus.”
The study is not without Kewitt: it was small, and did not specify participants’ race or sex, or whether they had underlying conditions. The tests looked for viral RNAs themselves, rather than genetic fragments of coronoviruses themselves. (Its genetic material is RNA, not DNA.)
Nevertheless, experts were anxious to learn that young children may take significant amounts of coronavirus.
“I have heard many people say, ‘Well children are not susceptible, children are not infected.” And it clearly shows that this is not true, ”said Stacey Schulz-Cherry, a virologist at St. Jude Children’s Research Hospital.
“I think this is an important, really important, first step in understanding the role that children are playing in transmission.”
Jason Kindrachuk, a virologist at the University of Manitoba, said: “Now that we are moving around at the end of July and trying to open schools next month, it really needs to be considered.”
The standard diagnostic test increases the genetic material of the virus in a cycle, with the signal intensifying every round. Initially, the more viruses the swab contains, the fewer cycles are needed for a clear result.
Dr. Heidel-Sergeant, who has a research interest in coronaviruses, began to see that children’s trials were coming up with lower “cycle thresholds” or CT, suggesting that their samples were with the virus.
Questioned, he called the hospital’s lab on Sunday and asked him to look at the test results for the past several weeks. He said, “It wasn’t even something we saw.”
He and his colleagues analyzed samples collected at the drive-through testing sites in Chicago and between April 23 and April 27 with nasopharyngeal swab, which showed symptoms of Kovid-19 among those who came to the hospital for any reason. .
He saw the swab taken from 145 people: 46 children under 5; 51 children between 5 and 17 years of age; And 48 adults between 48 and 18 years of age. Really sick children would be expected to be very critical of the virus, the team excluded children who needed oxygen support. Most children in the study reported only fever or cough, Drs. Said Heald-Sergeant.
To compare the groups objectively, the team consisted of only children and adults who had mild to moderate symptoms and for whom they were aware of the symptoms. Dr. The Heald-Sergeant excluded people who did not have symptoms and did not remember when they began to become ill, as well as those who had symptoms for more than a week before the test.
The results were confirmed by Dr. Heal-Sergeant Humps: Older children and adults had similar CTs, with an average of about 11 and up to 17 years of age. But children below 5 years had a low CT of about 6.5. The upper limit of the range in these children was a whistle of 12, though – compared to still older children and adults.
“This certainly suggests that virus levels in children are similar and probably even higher than in adults,” Dr. Heidel-Sargeant said. “It wouldn’t be surprising if they were able to shed the virus” and spread it to others.
The results are consistent with those from a German study of 47 infected children between 1 and 11 years of age, which showed that children who did not have symptoms had higher viral load than adults’. And a recent study in France found that asymptomatic children had similar CT values as children with symptoms.
Dr. Kindrachuk, who relied on this metric during the Ebola outbreak in West Africa, said the CT value is a reasonable proxy for the amount of coronovirus.
Frequently Asked Questions
Updated July 27, 2020
Should I refinance my mortgage?
- This can be a good idea, as mortgage rates have never come down. Refinance requests have pushed mortgage applications to some of the highest levels since 2008, so be prepared to get in line. But defaults are also coming up, so if you are thinking about buying a home, keep in mind that some lenders have tightened their standards.
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- It is unlikely that many schools will return to a normal time this fall, with the online learning mill required to continue child care and workdays. California’s two largest public schools – Los Angeles and San Diego – said on July 13, the instruction would only be in the fall, with concerns that increasing coronovirus infections in their areas also pose a threat to students and teachers. The two districts together enroll 825,000 students. They are among the largest in the country to drop plans for a partially physical return to classrooms when they reopen in August. For other districts, the solution would be an all-or-nothing approach. Several systems, including the nation’s largest, New York City, are preparing hybrid plans, including spending some days in classes and some days online. There is no national policy on this yet, so check in regularly with your municipal school system to see what is happening in your community.
What is Coronavirus Virus?
- Coronovirus can remain for hours in small drops in stagnant air, infecting people as they breathe, growing scientific evidence suggests. This risk is highest in crowded indoor locations with poor ventilation, and may help explain the super-spreading events reported in meatpacking plants, churches and restaurants. Linse Mar, an aerosol expert at Virginia Tech, said it is unclear how much spread of the virus through these small droplets or aerosols compares to larger droplets that cause a sick person to cough or sneeze or be exposed to contaminated surfaces Is expelled upon arrival. Aerosol is also released when a person without symptoms is a Dr. According to Marr and more than 200 other experts, he talks, speeches or narrates, which outlined the evidence in an open letter to the World Health Organization.
What are the symptoms of coronavirus?
Does Kovid-19 have asymptomatic transmission?
- So far, the evidence seems to show this. A widely cited paper published in April shows that people are most infected about two days before the onset of coronovirus symptoms and it is estimated that 44 percent of new infections were as a result of transmission from people who have yet to have symptoms Were not showing Recently, a top expert at the World Health Organization stated that transmission of coronovirus by people who did not have symptoms was “very rare”, but she later reverted to that statement.
Nevertheless, he and others stated that ideally researchers would develop infectious viruses from samples instead of testing them for RNA of the virus.
“I suspect that this would probably translate into a sense that there is more real virus out there, but we can’t say that without looking at the data,” said Juliet Morrison, a virologist at the University of California, Riverside.
Some RNA viruses multiply quickly and suffer from genetic errors that render the virus infecting cells inefficient. Some RNAs found in children may represent these “defective” viruses: “We need to understand how infectious the virus really is,” Dr. Shultes-Cherry said.
(Researchers say they do not have access to the type of high-security laboratory needed to develop the infectious coronavirus, but other teams have cultivated the virus from children’s samples.)
Experts all emphasize that the findings at least indicate that children may be infected. People who disturb a lot of the virus can spread it to teachers and other staff members of the school when they reopen it in their homes, or in schools.
Many school districts plan to protect students and staff members by implementing physical disturbances, cloth coverings, and hand hygiene. But it is unclear how staff members and teachers can prevent young children from getting too close to others, Dr. Kindrachuk said.
“Frankly, I just haven’t discussed much about how that aspect can be handled,” he said.
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Observations from schools in several countries have suggested that, at least in places with mild outbreaks and with preventive measures, children do not spread coronovirus efficiently to others.
Strong immune responses in children can limit both how many viruses they can spread to others and for how long. Children’s overall health, underlying conditions such as obesity or diabetes, and sex can also affect their ability to transmit the virus.
Some experts have suggested that children may transmit fewer viruses due to their small lung capacity, height, or other physiological aspects.
Dr. Morrison rejected those suggestions. The virus is shed from the upper respiratory tract, not the lungs, he noted.
“We’re going to reopen day care and primary schools,” she said. If these results hold up, “then yes, I would worry.”