FIGURE A9-1 Hierarchichal nature of traditional public health reporting.

This is a powerful system and one that is very good at capturing much information and funneling it towards people who can collect, digest, and process it. However, it is also a system that takes time and one in which any break in the chain can lead to the loss of information.

In contrast, the idea behind informal biosurveillance systems (Figure A9-2) is that they not only deal with a hierarchical system but also can communicate in both directions with many levels of the system, such as local health officials, laboratories, ministries, and the World Health Organization (WHO), in addition to healthcare workers in the field, the public, and the media. This kind of process can speed the flow of information and can improve our ability to detect outbreaks.

Shortly after ProMED began operating, it became clear that the space on the Internet was becoming larger and larger and that it really was not possible for a person to look at everything and see everything. The idea of web crawling, or using automated search systems to mine the Internet for early warnings of emerging diseases, was born.

One of the first systems in the public health domain was the Global Public Health Information Network (GPHIN), established by the Public Health Agency of Canada and still operated by this entity (Mykhalovskiy and Weir, 2006). GPHIN remains a large and robust system that alerts public health officials and agencies such as CDC and the WHO that use it on a paid subscription basis to find out information about emerging diseases.