Regardless of whether schools open with full-time in-person classes or a hybrid model, their success in preventing a new outbreak of COVID-19 from spreading will depend on their capacity to quickly find and isolate those who come to school sick.
Districts in at least five states have had to quarantine or stop in-person classes shortly after reopening after students or teachers turned up positive for the new coronavirus. Two new large studies in the United Kingdom and Australia suggest having a strict process for testing, quarantine, and contact tracing significantly reduces the likelihood of an outbreak after schools reopen.
In one study in the Lancet Child & Adolescent Health journal, U.K., researchers found that testing and contact tracing procedures at schools kept the infection curve flat in the months after reopening, but only if the procedures are strict and comprehensive enough. For example, if someone with symptoms or a high risk of COVID-19 received a rapid, one-day-turnaround test and after testing positive was immediately quarantined for 14 days, researchers found their likelihood of passing along the virus dropped by 90 percent.
The U.K. researchers modeled the total deaths countrywide over time based on six different scenarios for schools opening in-person classes full or part time, with different levels of testing and tracking ability. For example, if schools could accurately identify at least 75 percent of infected students who attend school part-time in-person, and could trace at least 40 percent of those who came in close contact with the infected person, researchers predicted no significant rise in COVID-19 deaths after schools reopen. But schools which open even part-time in-person classes with less rigorous testing could see a new wave of coronavirus deaths “two to three times the size of the original COVID-19 wave” peaking within a few months.
Similarly, an observational study also published in the Lancet looked at 25 schools and nurseries in New South Wales which had contact tracing and quarantine procedures in place while open. Researchers found that 27 children or teachers who attended with an active COVID-19 infection had close contact with nearly 1,450 people, but only infected 18 of them, or about 1.2 percent. Moreover, transmission from one staff member to another was significantly more likely than student-to-student infections.
Chris Bonell, a co-author of the U.K. study and a public health and policy researcher at the London School of Hygiene and Tropical Medicine, said the findings “should not be used to keep schools shut because of a fear of a second wave but as a loud call to action to improve the infection control measures and test and trace system so we can get children back to school without interrupting their learning again for extended periods of time. This is even more important in the context of opening up other areas of society.”
The two school studies align with a broader study in the journal Nature, which found rapid community testing, tracing, and quarantine requirements were key to safely reopening businesses and community activities after broad shutdown orders this spring.
Tracing Challenges
The Australian findings, at least, may be less applicable to U.S. schools, because that country has maintained much lower rates of the virus in their larger communities. More than 50,000 new U.S. cases of COVID-19 have been found in the last seven days, according to the Centers for Disease Control and Prevention, and the majority of states now have had more than 40,000 confirmed cases.
The Centers for Disease Control and Prevention call for schools to identify and notify any student (or staff member) who tests positive for COVID-19 and provide them information on how to isolate themselves for 14 days. Then tracers work with the initial infected student to identify every person who came within six feet of the student for 15 minutes or more, and ask them to get tested and potentially enter quarantine as well, for 14 days after their last contact with the infected person. During the isolation period, tracers check in daily on each person’s temperature and symptoms. Those who show symptoms of the coronavirus would be tested, and the entire cycle could continue until the outbreak is stopped.
The need for better monitoring has prompted districts like Los Angeles Unified to pledge regular coronavirus testing of all students and staff, an initiative the district says will cost about $150 million this school year, or $300 per student.
Robust tracking systems are likely to be a heavy lift for nearly a third of the districts whose reopening plans Education Week has analyzed, which plan to re-open school at least partly with in-person classes.
“The overlap between COVID-19 symptoms with other common illnesses means that many people with symptoms of COVID-19 may actually be ill with something else,” the CDC notes in its guidance to schools. “This is even more likely in young children, who typically have multiple viral illnesses each year. For example, it is common for young children to have up to eight respiratory illnesses or ‘colds’ every year. ... Excluding students from school for longer than what is called for in existing school policies (e.g., fever free without medication for 24-hours) based on COVID-19 symptoms alone risks repeated, long-term unnecessary student absence.” The agency also noted in August that people who have recovered from the virus may continue to test positive for up to three months.
