School COVID-19 mitigation strategies associated with low secondary transmission in Missouri pilot

This observational pilot investigation examined SARS-CoV-2 secondary transmission in K-12 schools implementing multiple COVID-19 mitigation strategies. The study was conducted in 22 participating schools in St. Louis County and the City of Springfield, Missouri, and included 102 tested close contacts of 37 persons with COVID-19. The primary outcome was detection of school-based secondary transmission.

The main finding was that school-based SARS-CoV-2 secondary transmission was detected. Specifically, transmission was identified in 2 of the 102 tested close contacts. The effect size, p-value, and confidence intervals for this finding were not reported. No comparator group was specified in the study design.

Safety and tolerability data, including adverse events and discontinuations, were not reported. The study authors noted this was an observational investigation reporting association, not causation. Key limitations include the pilot nature of the investigation, observational design, and limited sample size of 102 tested contacts. Funding sources and conflicts of interest were not reported.

For practice, the relevance of these findings was not explicitly stated. The low detected transmission rate in this specific setting with mitigation strategies may be of interest, but the evidence is preliminary. Clinicians should interpret these results with caution due to the study's design limitations and lack of generalizability beyond the specific Missouri school districts studied.