Bloomberg's insight into children and Covid
Children are typically "superspreader" of respiratory germs, which makes it puzzling that they do not appear to be the main transmitters of the coronavirus that causes Covid-19. They are relatively absent among hospitalized patients, which was initially thought to be due to the fact that they are less likely to become seriously ill once infected. Subsequent studies indicate that those of elementary school age, at least, may be less likely to contract the virus in the first place. With Northern Hemisphere schools and universities planning to reopen in August and September, scientists and public health authorities are trying to determine the role of young people in the spread of the pathogen and the best way to mitigate this threat – Bloomberg writes.
1. To what extent are children infected?
According to mid-year estimates, only 2% to 5% of individuals with laboratory-confirmed Covid-19 were under the age of 18. This is a percentage well below that age group of the global population, which is around 30%. Compared to adults, children with Covid-19 typically have milder symptoms that are mainly limited to the nose, throat and upper airways, and rarely require hospitalization.
2. Are the risks evenly distributed?
Maybe not. Children under the age of 10 are significantly less susceptible to the virus than teenagers and adults, according to research by scientists from the Harvard TH Chan School of Public Health in Boston and the University of St Andrews in Scotland, published earlier than peer review and publication in July. The susceptibility for children over the age of 10 was similar to that of adults, apart from those over the age of 60, who are most at risk. The results are corroborated by a study published in June that used antibody tests to interview 2,766 people in Geneva. The study found that teenagers are almost as likely to have been infected with the adult virus aged 20 to 49, while children ages 5 to 9 fell far behind.
3. Why might younger children be less sensitive?
There are several theories. Scientists speculated that Covid-19 could save children because they are less exposed to the virus, with school closings and other removal measures largely isolating them. It is possible for children to mount a stronger initial immune response to the virus, giving the body a better chance of rejecting it (and avoiding some complications that adults receive). It has also been speculated that the receptor that the virus uses to invade human cells is less mature in children, making it more difficult for it to cause an infection. Younger ones are less commonly affected by hypertension, type 2 diabetes and other chronic conditions known to increase the risk of serious Covid-19 disease. A low infection rate and mild symptoms among children were also observed during the first outbreaks of two other new coronaviruses, one in 2002-2003 which causes severe acute respiratory syndrome (SARS) and another from 2012 which causes Middle Eastern Respiratory Syndrome (MERS).
4. Do children spread the virus?
Trials are limited. In a highly cited study of 5,706 coronavirus patients and their contacts in South Korea, published on July 16, the researchers concluded that children under 10 years old spread the virus at the lowest rate. However, they found that children aged 10 to 19 are more likely to spread Covid-19 within a family than younger children and adults. The study had limitations. As with similar studies, the researchers first identified an infected person and then tested their contacts, which means they can't be sure who started the chain. In addition, the study was conducted while schools were mostly closed. In the United States, school closures have been associated with a 62% drop in Covid-19 cases and 58% deaths, researchers from the Children's Hospital Medical Center in Cincinnati reported in July. They acknowledged that the trends were greatest in states with a low cumulative incidence of Covid-19 at the time of school closings, and that part of the reduction may be due to other measures.
5. What happened where the schools were reopened?
The tests are preliminary and conflicting. Denmark and Norway reopened schools in April and avoided subsequent outbreaks. Health specialists link their success both to mitigation strategies, including smaller classes and increased hand washing, and to the fact that overall cases were low at the time. Germany reported older students in small groups to schools in early May, when the overall cases were moderately high and saw greater transmission among students, though not among school staff. In Israel, schools were completely reopened without restrictions on May 17. Ten days later, a serious high school epidemic occurred, followed by a significant wave of infections in the general population, which prompted the government to shut down parts of the economy again.
6. How much do children get sick?
Scientists from the London School of Hygiene & Tropical Medicine in June found that clinical symptoms manifest themselves in 21% of infections in children aged 10 to 19 years, rising to 69% in people over the age of 70. Death is extremely rare in children, although it can occur in those who are already very ill with cancer or other serious conditions. An uncommon but serious blood disorder has been associated with SARS-CoV-2, as the virus is called. Known as pediatric multisystem inflammatory syndrome (PIMS) or childhood multisystem inflammatory syndrome (MIS-C), it is a life-threatening condition, similar to Kawasaki disease. It occurs at a rate of around two in 100,000 people under the age of 21 – far less than the 322 out of 100,000 diagnosed with coronavirus infection in that age group.
(Excerpt from the foreign press review by Eprcomunicazione)
This is a machine translation from Italian language of a post published on Start Magazine at the URL https://www.startmag.it/mondo/bambini-e-covid-che-cosa-si-sa-report-bloomberg/ on Sat, 01 Aug 2020 06:00:54 +0000.