Tracking and understanding the patterns of H1N1's spread remains crucial as more dots show up on the GeoSentinel map, Freedman says. Member clinics log on to the network and submit disease cases through a standardized Internet form, which links to global positioning. Qualified researchers, doctors and others use those reports for pandemic modeling and monitoring, and to gain a big-picture look at disease transmission.

"The most striking thing is how rapidly the swine flu spread," Freedman says. "Although the H1N1 virus is fairly mild compared to a lot of other novel flu viruses, it is very contagious. Back in 1918 and 1919 when we had the great flu epidemic, it took six months or more to spread across the world.

"The new H1N1 swine flu spread across the world in six weeks."

One important pattern to emerge through GeoSentinel monitoring was naming North America as the early source for spreading H1N1 person-to-person, Freedman says. The initial surveillance data was continuously shared with public-health groups, governmental agencies and doctors who needed to respond swiftly to the pathogen.

"With the speed of modern travel, and the fact that our countries draw visitors from a lot of different nationalities, the ingredients for a pandemic were there. Americans were top of the list for exporting this disease," he says.

Source: University of Alabama at Birmingham