Large-scale randomized testing and contact tracing over time, which will give a more complete picture of how the virus is transmitted and how, has not yet been done in schools. In July, at the Journal of Emerging Infectious Diseases, researchers at the Korea Center for Disease Control and Prevention published the results of more than 59,000 contacts of 5,706 coronavirus patients. In children under 10, the virus was found to be much lower than between 10 and 19, with transmission rates comparable to adults. But in that initial cohort, only 3 percent of patients were 19 and younger, and after their testing it probably means they presented symptoms. It is still unclear whether asymptomatic children who are difficult to detect can spread the virus; It is also not clear whether there are differences in transmission between the ages of 10 and 19.
Epidemiologist Nicholas Davis of the London School of Hygiene and Tropical Medicine says, “The data we are getting from different sources is flawed and not necessarily pointed in the same direction.” He and his colleagues used a statistical method called Bayesian Findings to test several hypotheses about children and Kovid. These include premises that are infecting children, but are not showing symptoms and are less likely to infect children. Based on epidemiological data from China, Italy, Japan, Singapore, Canada and South Korea, the researchers concluded that the two premises were probably correct to an extent. Their findings, published in Nature Medicine in June, estimate that people under the age of 20 are nearly half of the age group to be infected, and that people between 10 and 19 years of age who get the virus, only 21 percent There will be clinical signs. They could not distinguish old age, nor say how likely a child is to infect others.
None of these studies addressed the impact of reopening schools on the spread of Kovid. In fact, when researchers at the University of Washington Department of Global Health and Epidemiology began compiling a summary of models from 15 other countries where students have returned, they found “very few” scientific publications on the subject and primarily Trusted news reports from. In almost all countries, he observed, schools adopted security measures, including face masks and social distinctions. None of the classes ran before national rates of infection fell significantly (except Sweden, keeping many schools open); There is no evidence to say what would be the result of opening schools in areas of the US where the virus is growing. According to a research by researchers at the University of Manchester and Public Health England, in Germany, where infection rates were higher than in other European countries, the return of older students coincided with an increase in infections among each other, but not staff.
In Israel after the schools reopened in early May, students and staff wore masks. But several weeks later, those rules were relaxed. According to Haaretz, outbreaks soon began, spreading the infection to thousands of schools, forcing many of them to close again. There is no “clear cause and effect” between mask removal and outbreaks, says the lead author of the summary, Brandon Guthrie, but it is “circumstantial evidence” that they provide some protection in classrooms. It also shows how schools can receive health guidance.