Online tools could help identify disease outbreaks earlier

March 12, 2009

Researchers from Ottawa and Boston have found that the Internet may have contained early signals of Canada’s recent Listeriosis outbreak. Their analysis, published in the Canadian Medical Association Journal (CMAJ), shows that internet searches using the word “listeriosis” spiked in mid to late July of 2008, almost a month before the outbreak was publicly declared.

“Internet scanning represents an important advancement in health surveillance and search term surveillance is a provocative new tool that has much potential but both merit further evaluation,” write the authors, Dr. Kumanan Wilson and Dr. John Brownstein. “Most importantly, these technologies may provide significant benefits to outbreak control at local, national and international levels, ultimately reducing the health consequences of these outbreaks.”

Dr. Wilson is an Internal Medicine Specialist at The Ottawa Hospital, an Associate Professor of Medicine at the University of Ottawa and a Scientist at the Ottawa Hospital Research Institute. He also holds a Canada Research Chair in Public Health Policy. Dr. Brownstein is affiliated with Children’s Hospital Boston and Harvard Medical School.

The World Health Organization relies on web-based data sources for daily disease surveillance. Tools such as the Global Public Health Intelligence Network, developed by Health Canada, and Program for Monitoring Emerging Diseases are used by public health officials. HealthMap is a free, real-time system that maps reports on emerging diseases across the globe. Applications such as Google Flu Trends, which examine trends in search terms that correlate with disease, represent an emerging new area of surveillance.

While online tools can be useful there are limitations, such as signal overload, false indicators of an outbreak, risk communication problems for public health officials and lack of Internet access in developing countries.

Adapted from a CMAJ press release