Public Health Surveillance Using Global Health Explorer.

We demonstrate an early version of a semantic web tool, Global Health Explorer (GHX), that can be used to conduct public health surveillance using Twitter. Our infrastructure can use any controlled vocabulary to extract term uses in Twitter and supports hypothesis formation and exploration of data sets using visual analysis. The resulting data, gathered in RDF, makes it possible to analyze term usage through both temporal and spatial dimensions. GHX uses the qb.js framework to visualize and explore these data across dimensions, intially time and location. This allows users of GHX to monitor terms from pre-existing ontologies to conduct public health surveillance. We have prototyped the use of GHX to monitor terms from the NCI Thesaurus related to in uenza-like illnesses.