Biology Reference
In-Depth Information
6.7 Limitations .................................................................................................. 125
6.8 System Utilization during a Disease Outbreak (Novel Influenza
A (H1N1))..................................................................................................... 126
6.9 Conclusions................................................................................................. 128
6.10 Future Work................................................................................................ 128
References............................................................................................................. 129
6.1 Introduction
A freely accessible, automated electronic information system, HealthMap was
developed in 2006 for organizing data on outbreaks according to geography,
time, and infectious disease agent (Brownstein et al. 2008). This organization
of data provides a structure to information flow that would otherwise be
overwhelming or would obscure important elements of a disease outbreak
(Keller et al. 2009). HealthMap relies on a variety of electronic media sources,
including online news sources through aggregators such as Google News,
expert-curated discussion such as ProMED-mail, and validated official
reports from organizations such as the World Health Organization (WHO)
(Brownstein et al. 2008).
6.2 Data Acquisition
Currently, the HealthMap system collects reports from 21 sources, which in
turn represent information from more than 20,000 Web sites, every hour, 24
hours a day allowing for real-time intelligence. An average of 300 reports
per day are collected, with approximately 85.1% acquired from news media
sources. Internet search criteria include disease names, symptoms, key-
words, and phrases (Brownstein et al. 2008). Fully automated, the system
uses text-mining algorithms to determine the disease category and location
of the outbreak. Alerts, defined as information on a previously unidentified
or currently ongoing outbreak, are geocoded to the country scale with prov-
ince-, state-, or city-level resolution for select countries. Surveillance is con-
ducted in several languages, including English, Spanish, French, Russian,
Chinese, Portuguese, and Arabic (Keller et al. 2009).
In order for the system to organize alerts by infectious disease agent, it
draws from a continually expanding dictionary of pathogens (human, plant,
and animal diseases) (Brownstein et al. 2008). Since words may have multiple
spellings, for example, the American “diarrhea” and the British “diarrhoea,”
this dictionary is continuously expanding with multiple patterns (Freifeld
et al. 2008).
