Instructional days missed were compared with days that would have been missed if all student contacts of confirmed COVID-19 cases had been quarantined for 14 days.īetween August 1 and November 30, 2020, when the Alachua County SARS-CoV-2 test positivity rate was 4.9%, 495 suspected student cases were tested and 257 (51.9%) were positive for SARS-CoV-2 infection. The percentage of COVID-19–positive contacts among elementary and middle school students vs high school students was compared using the Fisher exact test with statistical significance set at P < .05 (2-sided) using R version 3.4.1 and R Studio version (R Foundation for Statistical Computing for both). Students who returned to school after a negative test result were monitored for symptoms through day 14. The percentage of student contacts who tested positive on days 9 to 14 was determined. If no testing was administered, a 14-day quarantine was required. Asymptomatic students who tested negative on days 9 to 14 could return to school on the day following their negative test. 4 Student contacts of confirmed COVID-19 cases were quarantined and offered RT-PCR testing at day 3 (to exclude students who might have been infected at the same time as the confirmed case) and at day 9 testing was sometimes delayed to days 10 to 14. The methods for genetic testing of isolates have been described. The Alachua County Health Department provided reverse transcriptase–polymerase chain reaction (RT-PCR) testing of nasopharyngeal swabs for symptomatic students (suspected cases) and contact tracing for COVID-19–positive confirmed cases RT-PCR and rapid antigen test results from private physicians were included for case confirmation. A hybrid model of virtual and in-person instruction was offered 49% of students were enrolled for in-person instruction. Alachua County has 49 schools serving a population of 26 456 kindergarten through 12th-grade students. Signed informed consent was obtained from parents before sample collection. The project was reviewed by the University of Florida and the Florida Department of Health institutional review boards and was determined to meet the criteria for a public health surveillance activity exclusion.