Samenvatting
Introduction
Mass gatherings without COVID-19 safety measures are expected to increase
the local incidence of COVID-19 infections. The Carnival Halle 2022 (CH22)
was the first organized mass gathering in Belgium since the start of the
COVID-19 pandemic, and coincided with the loosening of sanitary measures
imposed by the government. The event ran from the 26th to 28th of March
and is characterized by parades and a special festive zone with local food
and beverage stands. To dampen the impact of the CH22 on the COVID-19
infections, the festive zone was enlarged and public awareness of social
distancing was promoted using posters and audible messages.
Methods
The purpose of our study was to compare the averaged 14-day incidence, to
the national average to estimate the effect of CH22 on the number of covid infections in the region. Based on expert opinion, the communities of interest
were determined to be the cities and communes of Halle, Sint-Pieters-
Leeuw, Beersel and Pepingen, hereafter called “Zennevallei”.
The 14-day averaged incidence data for the Zennevallei region was
retrospectively collected using the Vlaamse Zorgatlas and expressed in
infections per 100.000 citizens, starting 2 weeks before the event and ended
5 weeks after the event. Regional hospitalization rate was retrospectively
collected from the AZ Sint Maria Halle for this period.
Results
An increasing trend in incidence was observed in both groups before CH22.
The national incidence of COVID infections per 100 000 citizens topped off
in the week after CH22. As hypothesized, the Zennevallei incidence increased
and topped off 2 weeks later and returning to the Belgian baseline 4 weeks
after CH22. During this period there was no increase in regional COVID-19
hospitalizations.
Conclusion
Organization of mass gatherings without COVID-19 safety measures seems
to have an impact on the local incidence of COVID-19 infections, but no
increase in hospitalizations was observed. This effect is compatible with the
COVID-19 clinical course and incubation time, suggesting the CH22 event
as a probable cause. Our proposed explanation for the absence of increase
in hospitalizations is herd immunity due to the high degree of vaccination
in Belgium, as well as the relatively young and healthy target audience. Our
study is limited by the retrospective nature. Further research could include a
case-control prospective analysis with serological and variant surveillance.
Mass gatherings without COVID-19 safety measures are expected to increase
the local incidence of COVID-19 infections. The Carnival Halle 2022 (CH22)
was the first organized mass gathering in Belgium since the start of the
COVID-19 pandemic, and coincided with the loosening of sanitary measures
imposed by the government. The event ran from the 26th to 28th of March
and is characterized by parades and a special festive zone with local food
and beverage stands. To dampen the impact of the CH22 on the COVID-19
infections, the festive zone was enlarged and public awareness of social
distancing was promoted using posters and audible messages.
Methods
The purpose of our study was to compare the averaged 14-day incidence, to
the national average to estimate the effect of CH22 on the number of covid infections in the region. Based on expert opinion, the communities of interest
were determined to be the cities and communes of Halle, Sint-Pieters-
Leeuw, Beersel and Pepingen, hereafter called “Zennevallei”.
The 14-day averaged incidence data for the Zennevallei region was
retrospectively collected using the Vlaamse Zorgatlas and expressed in
infections per 100.000 citizens, starting 2 weeks before the event and ended
5 weeks after the event. Regional hospitalization rate was retrospectively
collected from the AZ Sint Maria Halle for this period.
Results
An increasing trend in incidence was observed in both groups before CH22.
The national incidence of COVID infections per 100 000 citizens topped off
in the week after CH22. As hypothesized, the Zennevallei incidence increased
and topped off 2 weeks later and returning to the Belgian baseline 4 weeks
after CH22. During this period there was no increase in regional COVID-19
hospitalizations.
Conclusion
Organization of mass gatherings without COVID-19 safety measures seems
to have an impact on the local incidence of COVID-19 infections, but no
increase in hospitalizations was observed. This effect is compatible with the
COVID-19 clinical course and incubation time, suggesting the CH22 event
as a probable cause. Our proposed explanation for the absence of increase
in hospitalizations is herd immunity due to the high degree of vaccination
in Belgium, as well as the relatively young and healthy target audience. Our
study is limited by the retrospective nature. Further research could include a
case-control prospective analysis with serological and variant surveillance.
| Originele taal-2 | English |
|---|---|
| Titel | Annual Congress Belgian Society of Emergency and Disaster Medicine (BESEDIM) |
| Redacteuren | Catheline Depuydt, Sabine Lemoyne, Patrick Van de Voorde |
| Plaats van productie | Brussels |
| Uitgeverij | Frontiers Media SA |
| Pagina's | 85 |
| Aantal pagina's | 87 |
| Volume | 1 |
| Uitgave | 1 |
| ISBN van elektronische versie | 9782832512265 |
| DOI's | |
| Status | Published - 18 mrt. 2023 |
| Extern gepubliceerd | Ja |
| Evenement | BeSEDiM Annual Congress 2023 - Thurn and Taxis, Brussels, Belgium Duur: 18 mrt. 2023 → … http://www.besedim.be |
Conference
| Conference | BeSEDiM Annual Congress 2023 |
|---|---|
| Land/Regio | Belgium |
| Stad | Brussels |
| Periode | 18/03/23 → … |
| Internet adres |