Facebook app shows how people swap germs

Good friends share things: experiences, advice and--like it or not--germs. "PiggyDemic," a new Facebook app, lets people spread virtual bugs to their friends on the social network, allowing scientists to study the impact of human interaction on how a virus mutates and travels from one person to another.

The app brings a social element into modeling outbreaks. While computer models are now used to simulate how viruses spread, the algorithms err in assuming that a virus is distributed equally among populations, according to the developers of PiggyDemic at Tel Aviv University. "HIV is concentrated in Africa; certain types of flu are widespread in North America and Asia," Dr. Gal Almogy, one of the developers of the app, said in a release. "Adding the element of human interaction, and looking at the social networks we belong to, is critical for investigating viral interaction."

Almogy, who worked on the app with Professor Nir Ben-Tal of the department of biochemistry and molecular biology at the university's George S. Wise Faculty of Life Sciences, argues that the spread of flu and other infectious disease is a "social phenomena." With its widespread use and digital interactions among users, Facebook provides an appropriate virtual setting to test this hypothesis.

"PiggyDemic" is parts interaction monitor, game and potential real-life outbreak tracker. To glean insights about viral interaction from users of the app, researchers employ network visualization software to track how virtual viruses are swapped among users. And the app keeps score of how many times a user spreads virtual viruses.

There are also potential public health benefits of the app, which could eventually be used to alert Facebook users of actual outbreaks. "People who have this software can report if they are actually ill," Almogy said in his group's release. "If we know who their friends are and the sequence of the infecting virus, we can figure out which virus they have and how it passes from one person to another."

- here's the report
- get the app here