key: cord-0717302-6qe5u1br
authors: Llibre, Josep M.; Videla, Sebastià; Clotet, Bonaventura; Revollo, Boris
title: Screening for SARS-CoV-2 Antigen Before a Live Indoor Music Concert: An Observational Study
date: 2021-07-20
journal: Ann Intern Med
DOI: 10.7326/m21-2278
sha: 9a4c780db0fb7ae8a82bf7c06fcb23acc885e741
doc_id: 717302
cord_uid: 6qe5u1br

nan

3 in the front left. Of these 6 persons, 3 were identified in contacttracing studies of known index cases who had not attended the concert; therefore, their contagion was unlikely to occur during the event. One woman who participated in the event was oligosymptomatic, though she tested negative in the pre-event Ag-RDT screening and again 48 hours after the event; 4 days after the concert, COVID-19 diagnosis was confirmed by PCR testing. Therefore, she presumably attended the event during the incubation period (4). The transmission source of the 2 remaining cases could not be identified.

Discussion: The pragmatic approach of the study precludes direct comparisons between the incidence rate observed among attendees and that of the background population. Epidemiologic information in public health records, used as an information source for both attendees and the background population, is built primarily from contact-tracing studies and may overlook asymptomatic cases, which may account for up to 40% of COVID-19 cases (5) . Despite these limitations, our data indicate that no remarkable transmission events occurred during the concert and support that Ag-RDT may be suitable for ruling out individuals with transmission risk at the time of testing rather than identifying infected individuals (1).

Our results build on our previously reported clinical trial data (2) and suggest that the implementation of same-day Ag-RDT screening, use of face masks, and improved ventilation can prevent high rates of SARS-CoV-2 transmission in indoor mass-gathering live concerts without physical distancing. These findings must be read in the context of a case study conducted in a community with low vaccination rates and a moderate infection rate. Nevertheless, they are a key step for creating safe environments in not only live music events but also other mass-gathering indoor events. Data Sharing Statement: The following data will be made available with publication: deidentified participant data (contact Jessica Toro; e-mail, jtoro@flsida.org). The following supporting documents will be made available with publication: statistical/analytic code and informed consent form (contact Jessica Toro; e-mail, jtoro@flsida.org). These data will be made available to anyone requesting them for Excel databases and after approval of a proposal with a signed data access agreement with no restrictions.

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