Severe Acute Respiratory Syndrome Coronavirus 2 Transmission in Intercollegiate Athletics Not Fully Mitigated With Daily Antigen Testing

Abstract

Background High-frequency, rapid-turnaround SARS-CoV-2 testing continues to be proposed as a way of efficiently identifying and mitigating transmission in congregate settings. However, two SARS-CoV-2 outbreaks occurred among intercollegiate university athletic programs during the fall 2020 semester despite mandatory directly observed daily antigen testing. Methods During the fall 2020 semester, athletes and staff in both programs were tested daily using Quidel’s Sofia SARS Antigen Fluorescent Immunoassay (FIA), with positive antigen results requiring confirmatory testing with real-time reverse transcription polymerase chain reaction (RT-PCR). We used genomic sequencing to investigate transmission dynamics in these two outbreaks. Results In Outbreak 1, 32 confirmed cases occurred within a university athletics program after the index patient attended a meeting while infectious despite a negative antigen test on the day of the meeting. Among isolates sequenced from Outbreak 1, 24 (92%) of 26 were closely related, suggesting sustained transmission following an initial introduction event. In Outbreak 2, 12 confirmed cases occurred among athletes from two university programs that faced each other in an athletic competition despite receiving negative antigen test results on the day of the competition. Sequences from both teams were closely related and distinct from viruses circulating in Team 1’s community, suggesting transmission during intercollegiate competition in Team 2’s community. Conclusions These findings suggest that antigen testing alone, even when mandated and directly observed, may not be sufficient as an intervention to prevent SARS-CoV-2 outbreaks in congregate settings, and highlight the importance of supplementing serial antigen testing with appropriate mitigation strategies to prevent SARS-CoV-2 outbreak in congregate settings.

Use cases for COVID-19 screening and surveillance with rapid antigen-detecting tests: a systematic review

“…The second most common type of testing was targeted screening of specific populations, including testing at airports and ports of entry, 12 23 universities (campuses, dormitories, athletics programmes) 24-27 , and mixed interventions. 13 28 29…”

“…Serial testing with Ag-RDTs was noted as a potential strategy to help compensate for limited sensitivity during early infection in some 37 46 but not all 27 of the studies that investigated this approach.…”

SARS-CoV-2 transmission during an indoor professional sporting event

“…This testing strategy may also include vaccinated participants, since vaccination does not necessarily prevent infection and dissemination of SARS-CoV-2 infection under all circumstances 22,23 . Antigen tests seem not to be sufficient to identify all potentially SARS-CoV-2 positive sport participants 24 . Consequently, in the future it appears to be important to carry out PCR tests for detecting possible asymptomatic SARS-CoV-2 infections amongst actively participating players especially prior to indoor sporting events in order to prevent the mass transmission of this disease.…”

Diagnostic accuracy of rapid point-of-care tests for diagnosis of current SARS-CoV-2 infections in children: A systematic review and meta-analysis

“…Whether a lower sensitivity can be compensated by frequent testing remains controversially discussed [3][4][5][6]. Further, the fact that sensitivity and specificity are no inherent test characteristics but are rather affected by various factors, including population characteristics, sample quality, and study design, needs consideration [7].…”

“…However, the advantages of antigen tests come at the price of lower diagnostic accuracy, most notably a lower diagnostic sensitivity, which increases the risk of missing cases, including pre-symptomatic infected individuals who have yet to enter the most infectious period [2]. Whether a lower sensitivity can be compensated by frequent testing remains controversially discussed [3][4][5][6]. Further, the fact that sensitivity and specificity are no inherent test characteristics but are rather affected by various factors, including population characteristics, sample quality, and study design, needs consideration [7].…”