FIGURE A9-4 Google Flu Trends screen shot.

SOURCE: See http://www.google.org/flutrends/us/.

to its May 5, 2009, entry, the first documented cases were in Mexico City, later found to be confirmed with swine flu.

Retrospectively, one of the earliest reports appeared on HealthMap on April 1, 2009, from the Veracruz region of Mexico, showing an outbreak of pneumonia in that region.

Other blog entries discuss the role of the traditional public health system, its detection of the swine flu outbreak through laboratory findings, and its response to it. But at the same time informal sources were used, including HealthMap and Veratect, for recording information on this outbreak early on.

The April 11, 2009, entry discusses the revised IHRs, which became effective in 2007. The revised regulations recognize and to some extent codify the use of informal sources as valid sources of information for world public health and allow countries to report on reportable diseases of potential public health and international importance.

This was a key event that took many years to accomplish and WHO and the World Health Assembly deserve great credit for allowing it to happen. ProMED’s first report on April 22, 2009, followed the MMWR publication of the swine flu cases in California.

Box A9-2 is a brief summary of the use of informal information sources in the context of this current outbreak. Informal surveillance systems played a relatively minor role and the traditional public health system worked quite well in terms of this outbreak. The systems that have been in place for what we all thought would probably be an avian flu outbreak functioned quite effectively.