title: Using network theory to identify the causes of disease outbreaks of unknown origin.
abstract: The identification of undiagnosed disease outbreaks is critical for mobilizing efforts to prevent widespread transmission of novel virulent pathogens. Recent developments in online surveillance systems allow for the rapid communication of the earliest reports of emerging infectious diseases and tracking of their spread. The efficacy of these programs, however, is inhibited by the anecdotal nature of informal reporting and uncertainty of pathogen identity in the early stages of emergence. We developed theory to connect disease outbreaks of known aetiology in a network using an array of properties including symptoms, seasonality and case-fatality ratio. We tested the method with 125 reports of outbreaks of 10 known infectious diseases causing encephalitis in South Asia, and showed that different diseases frequently form distinct clusters within the networks. The approach correctly identified unknown disease outbreaks with an average sensitivity of 76 per cent and specificity of 88 per cent. Outbreaks of some diseases, such as Nipah virus encephalitis, were well identified (sensitivity = 100%, positive predictive values = 80%), whereas others (e.g. Chandipura encephalitis) were more difficult to distinguish. These results suggest that unknown outbreaks in resource-poor settings could be evaluated in real time, potentially leading to more rapid responses and reducing the risk of an outbreak becoming a pandemic.
authors: EcoHealth Alliance, 460 West 34th Street, 17th Floor, New York, NY 10001, USA. daszak@ecohealthalliance.org
authors: Tiffany L
authors: TL
authors: Bogich
authors: Sebastian
authors: S
authors: Funk
authors: Trent R
authors: TR
authors: Malcolm
authors: Nok
authors: N
authors: Chhun
authors: Jonathan H
authors: JH
authors: Epstein
authors: Aleksei A
authors: AA
authors: Chmura
authors: A Marm
authors: AM
authors: Kilpatrick
authors: John S
authors: JS
authors: Brownstein
authors: O Clyde
authors: OC
authors: Hutchison
authors: Catherine
authors: C
authors: Doyle-Capitman
authors: Robert
authors: R
authors: Deaville
authors: Stephen S
authors: SS
authors: Morse
authors: Andrew A
authors: AA
authors: Cunningham
authors: Peter
authors: P
authors: Daszak
mesh_terms: D001210:Asia, Southeastern / Q000453:epidemiology; D021821:Communicable Diseases, Emerging / Q000175:diagnosis* / Q000453:epidemiology* / Q000635:transmission*; D003198:Computer Simulation; D003937:Diagnosis, Differential; D004196:Disease Outbreaks / Q000517:prevention & control* / Q000706:statistics & numerical data*; D006801:Humans; D008962:Models, Theoretical
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