Although major sporting events are great opportunities to bring people together, their sheer scale also means that significant health risks are involved, requiring special precautions. In this context, Santé publique France was asked to develop a risk map. To do this, our staff collaborated with international counterparts and partners to identify potential health risks, which is a key first step in effective surveillance. The mapping was based on a review of the scientific literature regarding mass gatherings, France’s experience hosting other mass gatherings such as the Rouen Armada and Euro 2016, and the health risks identified in France and internationally in 2024.

What are the health issues associated with mass gatherings?

• Large numbers of people are concentrated in the same place at the same time

• Temporary reception or catering facilities need to be set up

• A greater number of people are exposed to environmental risks in a given location

• Diseases not usually present in a country can be imported

• It is potentially more complex to implement prevention and control measures among a mobile population that speaks a variety of languages and has differing healthcare practices

• The event could potentially be the target of malicious acts

• An increased demand for care could lead to overcrowding of facilities and potentially lengthen waiting times

• There could be shortages of medicines sold in pharmacies due to higher demand

What are the main risks that have been identified?

• Natural and environmental risks (heat waves, air or water pollution, flooding, etc.)

• Risks of infection (arboviruses, outbreaks of food poisoning or other food-related infections, measles, Legionella, and other respiratory infectious diseases, etc.) as well as imported cases of highly contagious diseases or emerging diseases

• Technological risks (fire, explosion, etc.)

• Social risks (overdose, excessive alcohol consumption, etc.) or risks linked to collective behavior (crowd movements, etc.)

• Terrorism risks