Prevention of Covid-19: The most important variable when reopening schools

Many schools in the U.S. gambled on offering classes in person in early August, even as their states were still fighting over uncontrolled distribution of Covid-19.

At some of those schools it did not go well.

In the Cherokee County School District of Georgia, for example, there have been at least 80 positive cases since August 3, and more than 1,100 students, teachers, and staff have had to be quarantined. At the high school in Paulding County School District, which came to national attention after photos of halls filled with mostly maskless students went viral, several students and staff tested positive, forcing the school to adopt a hybrid model of personal and virtual learning to accept. In Atlanta, one second-grader tested positive the day after classes began; the same week a 7-year-old died with no underlying conditions to the virus.

Scientists have found clear evidence that children, especially those over 12, can and can transmit the virus, although the disease is generally milder than in adults. This means that school outbreaks can be a risk for students, teachers, and the wider community.

While many school districts that have reopened report students being infected, these initial cases may not have arisen in the classroom. “For most of these cases in Georgia, schools were not open long enough for the transfer to come from within the schools,” said Megan Ranney, an emergency physician and director of the Center for Digital Health at Brown University. t examines pediatric mental health.

However, infected students and staff who arrived in the first week of school have already asked for shutdowns and quarantines around the country; in Mississippi, more than half of the counties reported Covid-19 cases in teachers, staff, and students.

What is noteworthy is that health experts predicted that cases among young people would increase if schools reopened before community transfer was under control – yet many school districts progressed to each other. “This is exactly where we’re warned – if you have high levels of Covid in the community, your business will appear in schools just because people catch it in the community,” Ranney says.

And it is not just children, teachers, and parents who are at risk – school outbreaks can lead to broader outbreaks in communities of. In resint superspreading events in Ohio, for example, found that children between the ages of 6 and 16 were part of the chain of transmission, causing the virus to be passed on to other children and adults.

Jeff Gritchen / MediaNews Group / Orange County Register via Getty Images

The World Health Organization recommends that schools open only if less than five percent of those tested positive for a virus over a two-week period are positive. In the U.S., the cut for what is considered “safe” for reopening schools at present varies by state, but they all tend to look at similar factors: Oregon, for example, has said counties have fewer than 10 cases must have per 100,000 people for three weeks before classes start again. Arizona requires less than 100 cases per 100,000, as a two-week delay in cases, as well as meeting other standards such as hospital capacity.

By comparison, Georgia has had 2,236 cases per 100,000 people in the last seven days since August 16th. (You can check your own state rates at the Centers for Disease Control and Prevention here.) In Georgia, many schools are also open despite high positivity rates – the percentage of people being tested for Covid-19 who are positive result. The number of positive tests in Georgia per 100,000 people was also well above the general threshold that public health experts recommend for activities in person.

A recent study by the American Academy of Pediatrics and the Children’s Hospital Association found that 97,000 children in the U.S. received Covid-19 in the last two weeks of July – representing an increase of 40 percent, or nearly one-third of the total number of pediatric cases since the pandemic began. It is unclear whether this is an increase in actual infections or if more children, who are often asymptomatic, are now being screened when schools reopen.

Since testing in general is not yet sufficient to check for the virus in the US, the CDC says that the actual incidence of Covid-19 in children is not yet known. But like Tom Frieden, former director of the CDC, recently tweeted, children between 5 and 17 now have the highest positivity rate of all age groups. “Age groups are not an island,” he wrote. “Spreading in any group is a risk for everyone.”

The U.S. Department of Education does not publicly monitor Covid-19 cases in K-12 schools, quarantine students, deaths, or school closures. That led a Kansas teacher to create a Google table with Google with media reports to track positive cases of Covid-19 associated with schools in more than 40 states. It shows that more than 2,000 students, faculty, administrators, and staff have tested positive for Covid-19 since early July, and that teachers have already died in Mississippi, Alabama, and California.

Public health experts at the University of Texas at Austin recently published a report analyzing the possibility that students and teachers would become infected on the first day of school. They found that it largely depends on the size of the school and how prevalent Covid-19 is in that school’s community. Based on data from mid-July, her model suggests that in Texas, a school of 100 people in Denton County could expect one to two Covid-19 cases in the first week, while higher rates in Harris County are likely to account for four cases.

Hidalgo County, which currently has a 17 percent positive test percentage, looks even worse, with two to eight cases predicted. (Racial and economic differences contribute to these differences; Hidalgo County is 90 percent Latinx and has seen a disproportionate number of Covid-19 cases.) These numbers are constantly changing, but they show that with high enough levels of community transmission, you can pretty much guarantee that at least one person will go to school infected, which may expose others.

In other countries where data on outbreaks to school leavers are available, the impacts of school opening are mixed. In Denmark, reopening of schools for 2- to 12-year-olds did not diminish the country’s already minimal outbreak. But many precautionary measures were taken to limit transmission.

Denmark reopened primary schools with comprehensive security measures in place, such as delayed entry times. Students were placed in small groups to reduce interaction, and hotels and libraries were used as additional classroom space. Even the rate of infection has increased after Danish schools reopened, although not enough to reduce the total number of cases.

In Israel, new cases have skyrocketed since schools reopened two months ago, but the country has at the same time introduced other distance measures, making it more difficult to pinpoint the causes. There are many factors that can make schools safer again, such as mask-wearing, social distance, and regular testing, so it is difficult to directly compare school plans from different countries.

However, there is a definite trend: Countries such as Vietnam and New Zealand, which have generally done a good job of controlling proliferation, have successfully reopened schools. Others, with higher community transmission, such as Chile, have struggled.

With a new disease, it is important to look at the totality of the emerging body of research across different age groups, rather than individual research results. For example, a widely cited South Korean study reported in July found that adolescents may have spread the virus more then adults; an update from the same researchers this week found that some of the teenager’s impending transfer was likely due to families actually sharing outside exposure.

Overall, the sum of evidence – including independent studies from the US, Iceland and Germany – finds older children may be more likely to spread the virus than adults if they become infected. A recent literature review found that “opening of secondary / secondary schools is likely to contribute to the spread of SARS-CoV-2.” (The same review found that children under the age of 10 may be less susceptible to infection.)

Another review published in De Lancet highlights that adequate testing and contact tracing are essential for reopening of schools. That is currently not possible in many U.S. states, which still see positive positions up to 23 percent, along with extreme delays in test results.

Chethan Sathya, a pediatric surgeon and assistant professor of surgery at Cohen Children’s Medical Center in New York, says people seem to miss the point that having an incomplete picture of how Covid-19 affects children is not licensed. send them back to school to find out. Ranney points out that some states, such as New York and its home state of Rhode Island, currently have low test positivity, and that it may be safer to reopen schools in those areas. “The only possible way to reopen schools is with low rates of community transfer,” she says.

“Emerging data suggest that it is unsafe to send children and teachers to school buildings, even with safety protocols, if the prevalence of cases in the community is too high,” she says. If schools still choose to open, she adds, “it’s an ongoing experiment on children and staff.”

Lois Parshley is a freelance investigative journalist. Follow her reporting of Covid-19 on Twitter @loisparshley.

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