Non-communicable diseases and injuries are the leading cause of death and illness at mass gatherings (MGs) and a major public-health problem, with human stampedes and heatstroke the main reasons for loss of life at such events. The findings of the third paper in The Lancet Infectious Diseases Series on MGs health highlight large gaps in knowledge about many non-communicable health risks during MGs, and a lack of evidence about which public-health interventions work best.
"Strategies for government preparedness and those of various international agencies have focused mainly on the risks of communicable diseases because of their potentially huge consequences, and less on documenting the risks introduced by non-communicable diseases", explains Robert Steffen from the University of Zurich in Switzerland, lead author of the paper.
The authors note that the diversity of non-communicable risks, ranging from illness relating to drug and alcohol use to terrorism, present complex public health challenges for health systems and the organisers of such events.
Over the past 30 years, human stampedes and crush injuries have resulted in more than 7000 deaths and 14 000 casualties. During the 1985 Hajj, 2000 cases of heat stroke were reported that resulted in more than 1000 deaths in just a few days.
The risk of life-threatening cardiovascular events are also important, more than doubling during MGs that are linked with intense emotional stress such as the football World Cup in Germany in 2006.
The authors report that minor traumatic injuries and medical complaints including cuts, sprains, and headaches are the main causes of illness and the need for onsite medical care.
Other factors found to increase the risk of injury and illness include events that take place in developing countries, crowd density and mood, warm weather, and being young, old, or female.
Steffen and colleagues identify a number of efficient interventions including the provision of advice about the dangers of heat and air-conditioned environments to reduce the incidence of heat-related illness, and effective crowd control including real-time crowd tracking and structural changes to reduce the risk of stampedes.
But, they highlight that existing guidelines and recommendations include several methods of intervention, such as models for the prediction of onsite emergency medical care, that lack evidence for their effectiveness.
They say: "Until appropriate models are developed and successfully tested, most of the medical requirements will still be based on historical data that are specific to each event."
They conclude: "No one-size-fits-all solution exists for the mitigation of risks from non-communicable diseases at MGs. However, new rigorous research into the factors that increase the risks and best practices in the mitigation of those risks would contribute greatly to further understanding the complex dynamics of MGs."
Professor Robert Steffen, University of Zurich, Zurich, Switzerland. T) +41 79 292 7832 E) roste@ifspm.uzh.ch
Journal
The Lancet Infectious Diseases