CDC researchers see little evidence in-person school drives COVID-19 infection

FILE PHOTO: A school safety officer greets students as they return to New York City's public schools for in-person learning, as the global outbreak of the coronavirus disease (COVID-19) continues, at P.S. 506 in Brooklyn, New York

By Vishwadha Chander

(Reuters) - Studies in the United States and abroad found little evidence schools were spreading COVID-19 infections, showing a "path forward" to in-person classes, researchers from the U.S. Centers for Disease Control and Prevention (CDC) said on Tuesday.

The risk of catching COVID-19 in schools and whether to allow in-person learning or stick with online classes has been a hot topic of debate in many countries, including the United States.

While there had been some evidence of in-school transmission, "the preponderance of available evidence from the fall school semester has been reassuring," the researchers said in an opinion piece on the Journal of the American Medical Association (JAMA) Network. (

"As many schools have reopened for in-person instruction in some parts of the U.S. as well as internationally, school-related cases of COVID-19 have been reported, but there has been little evidence that schools have contributed meaningfully to increased community transmission," the CDC said.

The authors pointed in part to a new CDC study of rural Wisconsin schools, where student mask wearing was high. COVID-19 incidence in the 17 elementary through high schools was 37% lower than in the wider community, with no infections acquired at school among staff members.

"Given the findings of our data set, with proper precautions such as distancing and wearing face coverings, it seems that adult school staff members are unlikely to contract COVID-19 in the classroom," study author Amy Falk, from the Aspirus Hospitals and Clinics, said in an emailed response.

CDC scientists in JAMA said that closing schools could affect academic progress, mental health and access to essential services.

They said that mitigation measures such as universal mask use, social distancing, and ventilation were key to avoiding infection.

In the Wisconsin study, just seven of 191 cases (3.7%) identified among 5,530 students and staff members during the period of Aug. 31 to Nov. 29, 2020, were associated with in-school transmission, all in students, researchers reported.

Social distancing was required and mask-wearing was reported at more than 92%. Classes were taught in stable cohorts with both lunch and classes taking place indoors. No systematic COVID-19 screening was conducted in the schools or the community, though, and student mask wearing was charted by only some teachers, according to the Wisconsin study, published in the CDC's Morbidity and Mortality Weekly report.

The researchers found widespread virus transmission in the surrounding community during the study period, with 7% to 40% of COVID-19 tests from Wood County showing positive results.

COVID-19 incidence among students and staff members in the study translated into 3,453 cases per 100,000 in schools versus 5,466 per 100,000 in the wider community.

(Reporting by Vishwadha Chander in Bengaluru; Editing by Peter Henderson, Bill Berkrot and Rosalba O'Brien)