Internet-based surveillance helps confront infectious disease threats at mass gatherings

2010 Winter Olympics case study

Integrating real-time Internet-based infectious disease surveillance with knowledge of worldwide air traffic patterns could help in confronting infectious disease threats at mass gatherings, such as the Olympics and other large scale events, suggests an article in CMAJ (Canadian Medical Association Journal) http://www.cmaj.ca/cgi/doi/10.1503/cmaj.100093.

With the world's population approaching 7 billion and expanding global access to commercial air travel, mass gatherings of hundreds of thousands of people have become commonplace at events like the Hajj, G20 summits, the Olympic Games and other examples. This ease of large population movements through air travel can increase the spread of infectious diseases from one corner of the earth to another.

The article, based on the case fof the 2010 Vancouver Winter Olympic Games, proposes a tool that could be used to identify infectious diseases at their source and potentially help prevent the importation of infection into the site of the mass gathering.

During the 1991 International Special Olympic Games in the United States, an outbreak of measles was triggered by an athlete from Argentina, where a concurrent measles epidemic was underway.

"This integrated knowledge could be used to notify officials at the site of the gathering of an emerging international threat, and could potentially foster a culture of greater international cooperation by motivating cities and countries that share common risks of infectious disease threats to work collaboratively," write Dr. John Brownstein, Children's Hospital Boston and Dr. Kamran Khan, St. Michael's Hospital, Toronto lead authors of the paper.

The authors looked at historic patterns of international air traffic into Vancouver during the month of February to predict where travellers would be originating from during the Winter Games. While travellers came from more than 800 cities worldwide, almost two-thirds travelled from 25 centres on which the researchers concentrated real-time infectious disease surveillance. The authors accomplished this by integrating knowledge from BIO.DIASPORA and HealthMap - two independent systems focusing on global air travel and infectious disease surveillance respectively. No international infectious disease threats were identified that were deemed to pose a serious risk to the Games.

This collaborative model was developed by researchers from St. Michael's Hospital and the University of Toronto in Toronto, Canada; Children's Hospital Boston, Massachusetts Institute of Technology, Boston University and Harvard Medical School in the United States.

"The capability to integrate knowledge of worldwide air traffic patterns and intelligence from Internet-based infectious disease surveillance in real-time could significantly enhance global situational awareness of infectious disease threats," state the authors. They suggest further validation of this model should be done by applying it to future mass gatherings such as the G20 Summit in Ontario and the FIFA World Cup competition in South Africa, both taking place in June 2010.