Study population and setting
This study was an outbreak investigation of COVID-19 cases and SARS-CoV-2 transmission within eight public elementary schools in Cobb Country, Georgia. The outbreak investigation occurred between December 1, 2020 and January 22, 2021 and was led by the Cobb and Douglas Public Health (CDPH), the Georgia Department of Public Health (GDPH), and CDC. The investigation included approximately 24 school days within a school district that includes approximately 2600 students and 700 staff. COVID-19 cases among educators and students were either self-reported or identified by local public health officials, and were defined as a positive SARS-CoV-2 reverse transcription–polymerase chain reaction or antigen test result in a person who attended school in-person. Semi-structured interviews were conducted with the parents of students, educators, and school administration to collect information on symptoms and potential exposures. Close contacts were defined as those exposed to an index patient at school within 6 ft for >15 minutes per day during a 24-hour period while the index patient was infectious. The infectious period of an index case was 48 hours before to 10 days after symptom onset or, if asymptomatic, 48 hours before to 10 days after specimen collection.
Summary of Main Findings
Nine clusters were identified among 6 of the 8 elementary schools participating in this investigation. In each of the nine clusters, three or more epidemiologically linked COVID-19 cases were identified. The nine clusters included cases among 13 educators, 32 students, and 18 household members of persons with a school associated case. The median cluster size was six cases, with a range of 3-16. Among 69 household members of persons with school associated cases tested, 18 (26%) tested positive for SARS-CoV-2. Two of the clusters were determined to have potential educator-to-educator transmission, four clusters involved probable student-to-student transmission, and eight clusters involved probable educator-to-student transmission. All nine transmission clusters involved potential challenges in physical distancing, and five involved inadequate mask use.
This outbreak investigation leverages data from interviews conducted with the parents of students, educators, and administrators to help characterize transmission within the school as well as among household members.
There are several limitations to this outbreak investigation. Primarily, the period of this outbreak investigation overlapped with a holiday and school break, during which is often associated with travel, gatherings, and activities outside of the school. However, the considerations and potential impact of this school break and holiday were not discussed in this report, despite its potential role in the outbreak. The semi-structured interviews were used to characterize transmission and identify potential exposures. However, these interviews were conducted with the parents of students and may be subject to reporting bias from either the parent or the information obtained from the student by the parent. Therefore, student-to-student transmission may be underrepresented in this study. Further, testing of asymptomatic cases was not done, which may underestimate the number of cases.
This outbreak investigation helped to characterize transmission within elementary schools and identify potential opportunities for improved mitigation strategies.
This review was posted on: 14 May 2021