Studies show how to safely hold a large indoor rally

Spanish researchers have found in randomized trials that there was no COVID-19 infection after an indoor music event with appropriate public health precautions.

When mask use, proper air circulation, and rapid testing were all adopted, 0% of concert attendees were COVID-19 positive 8 days after the concert, compared to 1 who did not attend. Was less than% (control group). Reported by Josep Llibre, MD, PhD, and a colleague of German Trias iPujol at a university hospital in Badalona, ​​Spain.

Interestingly, 3% of participants in the control group were positive and 3% of the concert participants group were positive using a transcription-mediated amplification (TMA) test prior to the concert, but with a rapid antigen test. The authors write that it was negative. Lancet infection..

“These results confirm that with the implementation of these measures, these indoor events are not super-spread events as previously classified. In addition, the results are SARS-CoV-2 during the event. It does not support an increased risk of infection, “Libre said. Today’s MedPage..

Although this study made news when the authors shared their findings Via press releaseThis was the first time the results were published in a peer-reviewed journal.

The authors said this was the first randomized trial to assess the safety of indoor mass gatherings of live music concerts in the COVID-19 era, using tests to detect viral infections. The findings provide hope for the safe return of popular culture and music events to society through the use of precautionary measures.

The gold standard for COVID-19 testing is RT-PCR, which has high detection sensitivity, but it takes longer. However, due to its low cost and short travel time, rapid antigen testing helped point-of-care screening for the event of the day, despite its low sensitivity.

The TMA test also provides sensitive and rapid turnaround time, can test DNA / RNA infections, and exhibits performance comparable to RT-PCR tests.

This experiment was conducted on December 12, 2020. 960 adults aged 18-59 years from Spain were randomly assigned to the two groups. One group attended a five-hour indoor concert and one group returned home. There were 465 participants who participated in the concert and 495 who did not.

All participants were screened via a nasopharyngeal swab given 12 hours before participants attended the concert or returned home. Swabs were tested by rapid antigen test and further analyzed by cell culture and RT-PCR. The results of the rapid antigen test could be confirmed on the app within 15 minutes of wiping with a cotton swab to confirm eligibility.

If the patient was COVID-19 positive, lived with an elderly person, was immunodeficient, or had a significant pre-existing condition (cancer, hypertension, diabetes) within the last 2 weeks prior to the study Excluded. To include, the rapid antigen test had to be negative.

At the concert, temperature screening was conducted and participants were given N95 masks to wear. Social distance was not enforced, concert attendees were allowed to sing and dance, and all access doors remained open to enhance ventilation.

Hand sanitizers are available and security guards have enforced the protocol. Room temperature was about 68 ° F. The venue was attended by 58 staff and several artists, all tested by a rapid antigen test.

The follow-up took place eight days after the concert, with participants wiped with a cotton swab and retested. Patients received contact tracing before and after the event and submitted a health questionnaire.

The primary outcome was to assess the risk of COVID-19 infection at population meetings and to determine the difference in the incidence of COVID-19 infection confirmed by RT-PCR in 8-day participants between the two groups as the primary efficacy end. I evaluated it as a point.

Two members of the control group participants were positive for COVID-19 8 days after the concert (estimated incidence 0.31%, 95% CI 0.04% -0.73%), both with mild clinical illness. However, in an group of people who attended the concert, 0% of the participants were positive (estimated incidence 0.14%, 95% CI 0% -0.61%). The Bayesian estimate of the incidence between groups was -0.15% (95% CI -0.72% to 0.44%).

“Situation of [U.S.] Today, the full vaccination rate of the general population is over 50%, which is much better because it counts, “says Llibre. Today’s MedPage.. “In addition, the risk of outdoor mass gathering events is significantly reduced.”

Libre said further research is considering whether the face mask can be removed if access to the event is restricted to fully vaccinated or negative individuals.

The limitations of this survey include those conducted in Spain, where participants share common demographics, and their small size. Participants change their normal behavior while studying, Hawthorne effect.. In addition, the TMA test is sensitive to low detection thresholds, which can lead to false positives, the authors say.

The authors cited the need for future research to further assess the safety of large indoor meetings, and the need for larger additional trials.Libre said Today’s MedPage The UK is conducting up to 15 pilot studies based on these results, and the Netherlands has also launched a pilot concert program.