Related Experiment Video
Updated: May 10, 2026

Efficient SARS-CoV-2 Quantitative Reverse Transcriptase PCR Saliva Diagnostic Strategy utilizing Open-Source Pipetting Robots
Published on: February 11, 2022
Assessing COVID-19 Testing Strategies in K-12 Schools in Underserved Populations
Tyler Walsh1, Samantha Hayes, Jingxia Liu
1Author Affiliations: Department of Pediatrics, Nationwide Children's Hospital, Columbus, Ohio (Walsh); St. Jude Global Department, St. Jude Children's Research Hospital, Memphis, Tennessee (Hayes and Malone); Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, Missouri (Liu); Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, Missouri (Malone and Xu); Department of Pediatrics, Washington University in St. Louis School of Medicine, St. Louis, Missouri (Fritz, Bonty, Butler-Barnes, Evans, Montgomery, Mueller, Reyes, Reyes, Vestal, Wilcher-Roberts, and Williams); Department of Occupational Therapy, Washington University in St. Louis School of Medicine, St. Louis, Missouri (Harris); and Department of Pediatrics, The Ohio State University College of Medicine and Nationwide Children's Hospital, Columbus, Ohio (Newland).
Context:
The COVID-19 pandemic presented an unprecedented challenge for operations of schools in the US. In addition to masking and distancing, weekly testing for SARS-CoV-2 was recommended for students and staff during high SARS-CoV-2 transmission levels to provide an additional mitigation strategy to limit transmission.
Objective:
To assess testing strategies (weekly screening vs. symptomatic only) on SARS-CoV-2 infection rates in public middle and high schools predominantly attended by underrepresented minorities.
Design:
During the 2021-2022 school year, a cluster randomized trial was conducted among 16 middle and high schools from 5 public school districts. These schools were randomized into one of 2 intervention groups: Weekly screening testing + symptomatic testing (S + S) or symptomatic testing only.
Setting:
Public schools in St. Louis (Missouri).
Participants:
Students, staff, and family members of 16 middle and high schools.
Intervention:
Weekly screening + symptomatic testing or symptomatic only testing.
Main Outcome Measures:
Any positive test across all weeks [yes/no], number of tests, number of positive tests, and positivity test rate for each participant.
Results:
One thousand three hundred ninety individuals participated in this study. From the S + S schools, 894 (64.3%) individuals participated: 200 (15%) students, 353 (43%) staff, and 290 (37.5%) household members. Among the 496 (35.7%) participants from the symptomatic only schools, 183 (13%) students, 203 (47%) staff, and 83 (40%) household members participated. A total of 183 participants tested positive during the study period. When comparing school-based testing strategies, the positivity rates were not different between the 2 groups ( P = .25).
Conclusions:
This study did not show a benefit of weekly screening testing. Underlying disease risk or effectiveness of testing is considered however, notably the finding may be attributed to the inherent differences of identifying positive cases in each testing strategies. Finally, the participation rate in the study at the schools was low, which limits this finding.
