Post on 17-May-2015
description
Disease Outbreak Monitoring on the Web
Clark FreifeldResearch Software Developer
Harvard Medical School Children’s Hospital Informatics Program
www.healthmap.org
HealthMap Article Processing
Acquisition
>20,000 sites Every hour; 24/7
Clustering
Text Matching Similarity Score
Categorization
1700 disease patterns 5000 location patterns
Bayesian Filtering
6 million phrases 91% accuracy
Multi-Stream Alarming: Heat Index
Meta-alert composite score, based on Number of sources providing information at a particular
location Recentness of alert
Marker algorithm Exponentially weighted alerts Increase heat (redness) for more recent event and
higher impactlow high
Freifeld et al. J Am Med Informatics Assn. 2008.
Limitations of English-languageAlerts by country
1-USA: 43512-UK: 10183-Canada: 8804-China:737
English
Spanish
French
Russian
Case Study: Legionnaire’s in Spain
June 30thGoogle (ES) AlertAlert #1
July 2ndProMED-mail AlertAlert #2
July 4thGoogle (EN) AlertAlert #3
Early Stats
> 200 alerts per day
80,000 alerts so far
Alerts in 201 countries
175 disease categories
4 four languages English (60%) Spanish (20%) French (11%) Russian (9%)
Usage
500-600 visits per day100,000 unique visitors since 9/06 launch Top visitors: cdc.gov dhs.gov med.navy.mil, af.mil state.fl.us state.id.us
Public Health Resource
Various implementations
International Society for Infectious Disease
Liberty Science Museum, NYC
HHS Command Center
Tool for general population
Future Directions
Improve existing filtering algorithmsMore sensitive, noisy sourcesMore filters: number of cases, species affectedMore languagesCollaborative networks
Other areas: Environmental health Chronic disease Violence, conflict zones Pharmaceuticals
Your ideas
AcknowledgmentsChildren’s Hospital Informatics Program@ Harvard-MIT HST
John Brownstein, PhDKen Mandl, MD MPHBen Reis, PhDMikaela Keller, PhDIsaac Kohane, MD PhD
Carlo Venis (Wabash)Roger Araujo (Peru NMRCD)David Blazes (Peru NMRCD)Aranka Anema (UBC)Larry Madoff (ProMED)
Funding
Google Foundation
National Library of Medicine (NLM)
Centers for Disease Control and Prevention
Canadian Institutes of Health Research (CIHR)
Contact
clark.freifeld@childrens.harvard.eduwww.healthmap.org
www.chip.org