In-Depth: Why K-12 COVID testing matters for everyone, and how much we need

COVID testing in K-12 schools
Posted at 11:41 AM, Apr 30, 2021
and last updated 2021-05-01 00:23:39-04

SAN DIEGO (KGTV) -- As more adults get vaccinated, health experts say COVID testing in grade schools is more important than ever to contain the virus.

Without adequate testing in K-12 schools to detect symptomless cases in children, researchers forecast that transmission rates will remain high -- even with the majority of adults vaccinated.

That makes K-12 testing programs an important line of defense for everyone in the community, said Dr. Howard Taras, the district physician for San Diego Unified.

Because children are not yet eligible for vaccination, “they are the greatest harborers of potential disease,” he said. “If the disease is going to be passed around in the community, it'll be now the children rather than the adults that are driving it.”

San Diego Unified is mandating testing for teachers and staff, but public schools across the country have a problem: they can’t mandate testing for children.

“If a parent does not want their child tested, the district cannot withhold their education from them,” said Taras.

That means parents have to opt in to testing, virtually guaranteeing that some families won’t participate, either by choice or by falling through the cracks in the sign-up process.

That leaves school districts with an important decision: if you can’t test every kid, is it worth it?

Put another way: how many kids do you need to test to have an impact?

“I think the overriding message around testing is you don't need to eliminate every infection,” said Dr. David Rubin, the director of PolicyLab at Children’s Hospital of Philadelphia.

Dr. Rubin recently wrote an op-ed highlighting new research from a team of scientists that forecasted the impact of various levels of K-12 testing.

The researchers project that if schools can detect 10 percent to 20 percent of the silent infections in kids within the first three days, it’s like having 80 percent of the children vaccinated.

Spotting that fraction of cases early would slash the community-wide infection rate by more than two-thirds, they estimate.

“I think this study really revealed that you don't need to eliminate all the transmission occurring in places that kids gather. But if you can eliminate a fair amount of it, you can really contribute to keeping rates low throughout the community,” Dr. Rubin said.

Although public K-12 schools cannot condition enrollment on testing, schools can require testing before participation in extracurriculars like sports and special events like prom, he said. They can also offer testing as an incentive to allow quarantined students back on campus a few days early.

But whether that kind of ancillary testing will capture enough silent infections may depend on how often districts test.

San Diego Unified plans to test kids who opt-in every two weeks.

“I would say we need to test, say maybe 70 percent [of students] over the course of every two weeks,” said Dr. Taras. “We're far from that in this school district, and in some districts they're not doing any testing at all.”

San Diego Unified tested 2,529 students during the two-week period ending April 23. That’s less than 5 percent of the 51,932 students learning on campus.

But Dr. Taras thinks San Diego Unified can reach 70 percent of its kids tested by leaning on teachers to recruit more families, explaining the benefits to families and the broader community, and making the sign-up and scheduling process as easy as possible.

“Our challenge is to increase the number of children who volunteer to be tested routinely so that we can drive down not only disease spread in schools, but we can drive down disease spread in the community at large,” he said.