Only 3.7% of COVID-19 cases at 17 in-person K-12 schools in Wood County, Wisconsin, were tied to in-school transmission, and incidence was 37% lower than that in the surround community, according to a study published yesterday in the Morbidity and Mortality Weekly Report (MMWR).In a commentary in JAMA on the topic, experts from the Centers for Disease Control and Prevention (CDC) give recommendations for safe reopening in US schools.In-school transmission uncommonThe study, led by a physician from Aspirus Doctors Clinic in Wisconsin Rapids, used school and public health records to identify 191 COVID-19 cases in 4,876 students and 654 staff across five rural school districts.Only 7 of the 191 cases (3.7%), all of them in students, were