Mass gatherings occur in a range of public places (e.g., spiritual and cultural settings, theatres, sports arenas, festivals, conference halls) and result in a large number of people being in close contact for extended periods of time. Mass gatherings can contribute to the transmission of respiratory pathogens, such as the virus causing the current outbreaks of COVID-19. However, mass gatherings are not homogenous and the risk must be assessed on a case-by-case basis by Public Health Authorities, event organizers and relevant planners. Cancelling large events may be recommended from a public health perspective, but compliance and sustainability may be difficult and may cause significant social disruption and public resistance.
PHAC recommends conducting a risk assessment when determining the public health actions related to a mass gathering during the COVID-19 outbreak. This involves assessing the epidemiology, related impacts, and the weight (importance) of each of the factors involved in the risk assessment. The rationale for the potential health risks of mass gatherings include: increased crowd density, restricted points of access/exit which force participants through high touch areas (e.g. doors, elevators), and limited medical care. The diversity of spectators and participants can be varied which can increase the risk of communicable disease transmission due to close contact with people who have a diverse risk factors and/or immunological status. Limited environmental cleaning and the potential for individual health measures (e.g. hand hygiene) may play a role in increasing health risks at mass gatherings.
This tool was based on advice contained in the World Health Organization’s mass gathering guidanceFootnote1. Public Health Guidance on COVID-19 is available on Canada.ca/coronavirus, with community-based measures (including mass gatherings).
Decisions regarding mass gatherings can be considered on a continuum from no changes needed, to enhanced communication to attendees, to risk mitigation strategies being employed without cancelling the event, through to postponement or cancellation of the event.
Risk mitigation strategies could include:
- reducing the number of participants or changing the venue to prevent crowding;
- staggering arrivals and departures;
- providing packaged refreshments instead of a buffet;
- increasing access to handwashing stations;
- promoting personal protective practices (hand hygiene, respiratory etiquette, staying home if ill);
- offering virtual or live-streamed activities; and
- changing the event program to reduce high risk activities such as those that require physical contact between participants.
Since mass gathering events, their settings, and participants/attendees are generally unique, the advice varies regarding which measures should be implemented. Public health authorities and event organizers must work together to assess the situation. The following risk considerations related to the event, the disease and the environment/setting are provided to promote a systematic review of risk and to inform decision-making. The classic epidemiologic triad contributes to the framework for risk assessment by highlighting the interplay between the host (in this case, the mass gathering event), the agent (SARS CoV 2 causing COVID-19) and the environment/setting (the broader context of the gathering in terms of its geographic location and associated resources).