K. Kutsar, Editor-in-Chief Citation: Kutsar K. Public Health Preparedness in Mass Gatherings. EpiNorth 2012;13:88-90.
Mass gatherings are defined as public events of limited duration that are planned in advance and are attended by more than 25,000 people (1). The most known mass gatherings are large sports events (olympic games, world and continental championships), artistic events (concerts and festivals), religious festivals (hajj), social events and political assemblies.
Possible public health risks resulting from by mass gatherings are communicable disease transmission and outbreaks, health problems associated with weather conditions, chronic disease (e.g. asthma and heart disease) exacerbation, drug- and alcohol-related problems, accidents, injuries occuring from stampedes masses being crushed together and (bio)terrorism.
Communicable diseases are especially relevant in the context of international mass gatherings. Pathogens may be introduced into the host country by visitors originating from endemic countries or diseases due to endemic pathogens circulating in the host country or a local outbreak may spread among those attending mass gatherings.
Communicable disease outbreaks at international mass gatherings have occured all over the world (2). These outbreaks have primarily been food-borne diseases (salmonellosis, shigellosis, campylobacteriosis and hepatitis A), respiratory infectious diseases (influenza, meningococcal disease, measles, pertussis, mumps, etc.) and environmental diseases (legionellosis, leptospirosis, etc.).
The public health system of the host country should be prepared for mass gatherings. Risk assessement is an important step in the prepareness. The basic indicators of health risk assessment are health care service availability, type and duration of event, assembled population size and density, degree of crowding, weather conditions, indoor or outdoor event, environmental hygiene level, morbidity (including the incidence of communicable diseases and outbreaks), potential spread of infection, effect of infection on the community, expected public awareness and political importance.
Health risk assessment is followed by a plan of action. Key components of the action plan are epidemiological surveillance, availability and preparedness of a clinical microbiology laboratory surveillance system, infrastructure, organization of control and prevention activities, organization of health care services and management of communicable disease cases, and preparedness for additional development of a syndromic surveillance system.
Epidemiological surveillance should be enhanced by epidemic intelligence to enable early warning of potential public health threats. Epidemic intelligence is defined as all activities related to early identification of potential health threats, verification, assessment and investigation that are performed in order to control health challenges (3). Epidemic intelligence should also include non-communicable health hazards.
Syndromic surveillance is a variant of surveillance that uses non-conventional sources of information (hospital emergency department visits, ambulance service calls, laboratory tests requested, web page hits related to health topics, job and school attendance and absenteeism). Two new real-time syndromic surveillance schemes were implemented to enhance the epidemiological surveillance system for the London 2012 Olympic and Paraolympic Games: 1) hospital emergency department syndromic surveillance system (real-time monitoring of attendance data) and 2) general practitioner out-of-hours/unscheduled care syndromic surveillance system (daily reports of patients presenting to GP services) (4). The new enhanced syndromic surveillance system provided England and Wales with one of the most comprehensive public health-based syndromic surveillance programmes in the world.
Mass gatherings always involve a number of high public health risks. Thus a high level of public health preparedness is required to cope with potential communicable disease transmission, outbreaks and other health hazards during mass gatherings. Risk communication is important; reports on public health and the epidemiological situation should be available to decision makers and the public. A high level of transparency contributes to general awareness and building of trust between responsible authorities and the public. References
1. Lombardo J et al. Public health surveillance for mass gatherings. John Hopkins APL Technical Digest 2008;27:347-355. Available online: http://www.jhuapl.edu/techdigest/TD/td2704/LombardoMassGatherings.pdf
2. Abubakar I et al. Global perspectives for prevention of infectious diseases associated with mass gatherings. Lancet Infect Dis 2012;12:66-74.
3. Kaiser R et al. What is epidemic intelligence, and how it is being improved in Europe? Euro Surveill 2006;11:E060202.
4. HPA Real-time Syndromic Surveillance Team. New real-time syndromic surveillance schemes operational ahead of London 2012 Olympic and Paraolympic Games. HPA Report 2012;6:17.