To reduce the number of students sent home to quarantine after exposure to the coronavirus, the Billings Public Schools, the largest school district in Montana, came up with an idea that has public health experts shaking their heads: Reshuffling students in the classroom four times an hour.
The strategy is based on the definition of a “close contact” requiring quarantine — being within six feet of an infected person for 15 minutes or more. If the students are moved around within that time, the thinking goes, no one will have had “close contact” and be required to stay home if a classmate tests positive.
Greg Upham, the superintendent of the 16,500-student school district, said in an interview that contact tracing had become a huge burden for the district, and administrators were looking for a way to ease the burden when they came up with the movement idea. It was not intended to “game the system,” he said, but rather to encourage the staff to be cognizant of the 15-minute window.
In an email to administrators last week, Mr. Upham encouraged staff members to “whenever possible, disrupt the 15-minute timeline through movement, distancing, and masking.”
Infectious disease experts say that moving students around every few minutes is actually more likely to increase transmission of the virus, by exposing more people to an infected student. It will also complicate contact tracing efforts, they said.
“That is not an evidence-based practice or sound scientific policy,” said Dr. Jennifer Nuzzo, an epidemiologist at the Johns Hopkins Center for Health Security who has been supportive of reopening schools for in-person instruction.
The 15-minute, six-foot definition is a guideline for identifying who might be at greater risk of infection, not a hard-and-fast rule about when it can or cannot happen, Dr. Nuzzo said, adding that a person can certainly become infected in less time or from farther away, especially indoors.
Dr. Sarah Fortune, chair of the department of immunology and infectious diseases at Harvard’s school of public health, said the 15-minute definition was meant to help contact tracers “effectively and efficiently identify people with the highest risk and target intervention to them.”
Kelly Hornby, principal of Billings West High School, wrote in an email to his staff last week that moving students around every few minutes and then returning them to their original desks would help dissipate airborne droplets containing the coronavirus, to the point “where the risk of being contaminated is greatly reduced.”
Dr. Fortune disagreed with that idea. “The particles that transmit Covid, they hang out in the air, and they spread through the air, and the aerosols can hang out for a very long time,” she said. “So stirring that air up or moving around from your spot doesn’t really limit your exposure or risk.”