Abstract
BACKGROUND: To inform prevention strategies, we assessed the extent of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission and settings in which transmission occurred in a Georgia public school district. METHODS: During 1 December 2020-22 January 2021, SARS-CoV-2-infected index cases and their close contacts in schools were identified by school and public health officials. For in-school contacts, we assessed symptoms and offered SARS-CoV-2 reverse-transcription polymerase chain reaction (RT-PCR) testing; performed epidemiologic investigations and whole-genome sequencing to identify in-school transmission; and calculated secondary attack rate (SAR) by school setting (eg, sports, elementary school classroom), index case role (ie, staff, student), and index case symptomatic status. RESULTS: We identified 86 index cases and 1119 contacts, 688 (61.5%) of whom received testing. Fifty-nine of 679 (8.7%) contacts tested positive; 15 of 86 (17.4%) index cases resulted in ≥2 positive contacts. Among 55 persons testing positive with available symptom data, 31 (56.4%) were asymptomatic. Highest SARs were in indoor, high-contact sports settings (23.8% [95% confidence interval {CI}, 12.7%-33.3%]), staff meetings/lunches (18.2% [95% CI, 4.5%-31.8%]), and elementary school classrooms (9.5% [95% CI, 6.5%-12.5%]). The SAR was higher for staff (13.1% [95% CI, 9.0%-17.2%]) vs student index cases (5.8% [95% CI, 3.6%-8.0%]) and for symptomatic (10.9% [95% CI, 8.1%-13.9%]) vs asymptomatic index cases (3.0% [95% CI, 1.0%-5.5%]). CONCLUSIONS: Indoor sports may pose a risk to the safe operation of in-person learning. Preventing infection in staff members, through measures that include coronavirus disease 2019 vaccination, is critical to reducing in-school transmission. Because many positive contacts were asymptomatic, contact tracing should be paired with testing, regardless of symptoms.