# 4004
With the Hajj later this month, the XXI Olympic Winter Games in Vancouver early next year, the Superbowl XLIV in January, Carnival in Rio, Mardi Gras in New Orleans and many other mass gathering events planned around the world – an influenza pandemic is a serious complicating factor.
The World Health Organization has released an 8-page guidance document entitled:
Interim planning considerations for mass gatherings in the context of pandemic (H1N1) 2009 influenza
Publication date: November 2009
Download the document [pdf 163kb]
In the Introduction, the authors lay out the intent of the document.
Introduction
Mass gatherings are highly visible events with the potential for serious public health and political consequences if they are not planned and managed carefully. There is ample documentation that mass gatherings can amplify and spread infectious diseases.
Respiratory infections, including influenza, have been frequently associated with mass gatherings. Such infections can be transmitted during the mass gathering, during transit to and from the event, and in participants’ home communities upon their return.
Planners of mass gatherings face special challenges during a global influenza pandemic. The purpose of this document is to outline key planning considerations for organizers of mass gatherings in the context of pandemic (H1N1) 2009 influenza. It should be used in conjunction with WHO’s Communicable disease alert and response for mass gatherings.
This document was prepared during September – October 2009 by WHO staff. It was reviewed by WHO's Virtual Interdisciplinary Advisory Group on Mass Gatherings. It is based on currently available information about pandemic (H1N1) 2009 influenza. As the pandemic situation evolves and additional information becomes available, it may be necessary to revise the document. Review of the document is planned in the first quarter of 2010.
Without speaking directly to whether any specific type of event should be cancelled or modified, they authors do recommend that a risk assessment be undertaken before an event is to proceed.
Risk assessment
The decision to proceed with a mass gathering or to restrict, modify, postpone, or cancel the event should be based on a thorough risk assessment. Event planners should undertake such an assessment in partnership with local and national public health authorities. The risk assessment should take into account available information about pandemic (H1N1) 2009 influenza at global, national, and local levels.
As part of the risk assessment, some factors may be of particular relevance such as:
- Influenza activity: The level of pandemic influenza activity circulating in the community where the mass gathering is to be held should be considered. However, it is difficult to predict the level of activity and which strains of influenza will be circulating very far in advance. WHO provides weekly updates of pandemic activity.
- Period of time over which the mass gathering will take place: If the duration of the mass gathering is more than the typical incubation period for pandemic (H1N1) 2009 influenza (2-3 days), then the majority of event-associated cases would be expected to occur while the mass gathering is underway. In contrast, if the duration of the event is shorter, most cases would likely occur after the event as people travel and return to their home communities.
- Age of participants: Since younger age groups appear to be more affected, mass gathering comprised principally of children and young adults may be associated with increased transmission compared with those comprised of older age groups.
- Occurrence of severe disease and health care capacity: Although severe disease is uncommon, treatment of these patients is challenging and resource intensive with emergency departments and intensive care units experiencing a disproportionate burden.
The document then goes on to discuss what steps event organizers can take to reduce the transmission of the pandemic virus, or cope with influenza cases.
