SALT LAKE CITY, Utah – Students across the country have returned to classrooms, but whether they stay there may depend on how well their schools control COVID-19.

Utah was the first in the nation to try out the "Test to Stay" protocol last school year.

The goal is to keep negative-testing kids in school rather than send them home during an outbreak.

Kids at Kearns High School in Kearns, Utah, started learning in person about a month ago.

Last year, the school tried the Test to Stay strategy in a pilot program.

Once the number of COVID-19 cases reached a certain threshold, it tested everyone for the virus over a two-day period.

"At that point in time, we were able to continue on with the school year with those who tested negative," said Granite School District spokesman Ben Horsley.

Kearns High School in Kearns, Utah, tested all students under the "Test to Stay" pilot program Dec. 7-8, 2020. Now, the Test to Stay protocol is written into state law.

Kearns High School in Kearns, Utah, tested all students under the "Test to Stay" pilot program Dec. 7-8, 2020. Now, the Test to Stay protocol is written into state law. (Granite School District)

After the pilot testing, the Utah legislature wrote the protocol into law in March.

Schools with 1,500 or more students must test everyone if 2% of the student population has COVID-19. Schools with fewer than 1,500 students must test everyone if 30 or more people have COVID-19.

"Once that threshold has been hit, we’ll come and conduct a sweep of the entire student population," said Maggie Graul, the program manager for the K-12 testing program at the Utah Department of Health.

"It’s absolutely possible that schools could be hitting that Test to Stay threshold multiple times throughout the school year," she added.

The state department of health has provided the tests and personnel.

Four schools in Utah hit the threshold last week, prompting a Test to Stay event. In total, they conducted about 3,600 tests. Ninety were positive.

Meanwhile, Kearns High School has stayed in the clear for now, with fewer than five active COVID-19 cases. It would begin a Test to Stay event if the number of active cases were to reach around 46.

"This is the main protocol we’re hanging our hat on in terms of if there is an outbreak, this is what we’ll utilize to identify potential cases," Horsley said.

Utah is among the states that enacted a ban on schools from requiring masks.

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Kids who test positive are still required to quarantine at home for 10 days.

While schools in Utah used Test to Stay last school year, the protocol is a recent development for schools in other areas such as Marietta, Ga. Some schools in southwest Ohio and northern Kentucky are using the strategy as well.

But Test to Stay may look different in each area. 

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In Utah, the testing is done until the case count reaches the threshold again. Schools in other states may test daily.

Parents should contact local health departments and school districts for safety and health guidelines.