CDC Endorses Covid-19 Test-to-Stay Strategy for K-12 Schools

“Test-to-stay is an encouraging public-health practice to keep our children in school,” CDC Director

Rochelle Walensky

said.

She added that the policy should be implemented alongside other prevention measures, such as regular testing, wearing a mask, monitoring close contacts of a positive case for symptoms and staying home if a student became ill.

More schools have adopted the strategy in the past several months, before the CDC endorsed the practice as an alternative to mandatory quarantines for children exposed to a known Covid-19 case, a policy which kept students home for up to 10 days.

About a dozen of the largest 100 school districts in the country have implemented test-to-stay, said Bree Dusseault, a principal at the Center on Reinventing Public Education, a research organization based in Seattle that tracks school responses to Covid-19. That number is up from early October, when five districts were using it.

“I would not be surprised if more districts adopt this approach in the new year as districts get ready for more potential infections in their community due to Omicron,” she said.

Among the same 100 districts, less than half require some or all staff to be vaccinated. Detroit’s public-school district this week mandated vaccination for all employees by Feb. 18.

The CDC released two reports highlighting the usefulness of test-to-stay when implemented alongside other prevention measures. Officials said vaccination remains the primary defense against Covid-19 for everyone who is eligible. The CDC reiterated that all children ages 5 years and older should get vaccinated and that adolescents ages 16 years and older should get a booster shot at least six months after their last dose.

One report reviewed cases in Lake County, Ill., after the Illinois Department of Public Health offered test-to-stay as an option for schools this fall. Ninety schools signed up, and about 97% of eligible students who were exposed to a Covid-19 case in school participated. Out of about 1,000 close contacts who participated, only 16 students ended up testing positive, the CDC said.

None appeared to transmit to other in-school contacts but some did transmit the virus to members of their household, resulting in nine additional cases. Researchers estimated that the program saved more than 8,000 in-person school days.

The second report tracked test-to-stay in Los Angeles County, where about half of school districts allowed the regime and one in five public schools participated. Covid-19 rates didn’t increase among the schools that implemented test-to-stay, while those that didn’t participate lost days in the classroom.

The updated guidance comes as many K-12 schools hope to avoid further disruptions to learning as the pandemic rages on and more cases of the Omicron variant are detected across the U.S. A handful of colleges and universities have reinstated remote learning and are requiring booster vaccination shots amid a sharp rise in Covid-19 cases on several campuses.

Under most test-to-stay plans, children are tested for Covid-19 daily or every other day after contact with a positive case. Students are sent home only if they develop symptoms or a test comes back positive, rather than having to quarantine for lengthy periods.

Although the CDC said test-to-stay was a useful alternative to home quarantine, officials noted that some schools, especially those with fewer resources, may struggle to implement the policy. Schools, for example, might not have the resources to space students 6 feet apart while they are maskless during lunch, which would disqualify them for test-to-stay under some programs. Some also reported a shortage of testing supplies, requiring students and staff to access testing off-site.

Many schools in Los Angeles County cited resource-related reasons for not joining, including staffing challenges and the ability to monitor for mask use.

The CDC said data on the effectiveness of test-to-stay might also vary for areas with lower vaccination rates and where transmission of Covid-19 has been higher.

—Douglas Belkin contributed to this article.

Write to Sabrina Siddiqui at Sabrina.Siddiqui@wsj.com and Brianna Abbott at brianna.abbott@wsj.com