  In severe outbreaks such as Ebola, bird flu and SARS, people share news, and
their thoughts and responses regarding the outbreaks on social media.
Understanding how people perceive the severe outbreaks, what their responses
are, and what factors affect these responses become important. In this paper,
we conduct a comprehensive study of understanding and mining the spread of
Ebola-related information on social media. In particular, we (i) conduct a
large-scale data-driven analysis of geotagged social media messages to
understand citizen reactions regarding Ebola; (ii) build information
propagation models which measure locality of information; and (iii) analyze
spatial, temporal and social properties of Ebola-related information. Our work
provides new insights into Ebola outbreak by understanding citizen reactions
and topic-based information propagation, as well as providing a foundation for
analysis and response of future public health crises.
