EcoHealth

, Volume 7, Issue 3, pp 283–293

Ecological Modeling of the Spatial Distribution of Wild Waterbirds to Identify the Main Areas Where Avian Influenza Viruses are Circulating in the Inner Niger Delta, Mali

  • Julien Cappelle
  • Olivier Girard
  • Bouba Fofana
  • Nicolas Gaidet
  • Marius Gilbert
Original Contribution
  • 366 Downloads

Abstract

Predicting areas of disease emergence when no epidemiological data is available is essential for the implementation of efficient surveillance programs. The Inner Niger Delta (IND) in Mali is a major African wetland where >1 million Palearctic and African waterbirds congregate. Waterbirds are the main reservoir of Avian Influenza Viruses (AIV). Our objective was to model their spatial distribution in order to predict where these viruses would be more likely to circulate. We developed a generalized linear model (GLM) and a boosted regression trees (BRT) model based on total aerial bird counts taken in winter over 6 years. We used remotely sensed environmental variables with a high temporal resolution (10 days) to predict the spatial distribution of four waterbird groups. The predicted waterbird abundances were weighted with an epidemiological indicator based on the prevalence of low pathogenic AIV reported in the literature. The BRT model had the best predictive power and allowed prediction of the high variability of waterbird distribution. Years with low flood levels showed areas with a higher risk of circulation and had better spatial distribution predictions. Each year, the model identified a few areas with a higher risk of AIV circulation. This model can be applied every 10 days to evaluate the risk of AIV emergence in wild waterbirds. By taking into account the IND’s ecological variability, it allows better targeting of areas considered for surveillance. This could enhance the control of emerging diseases at a local and regional scale, especially when resources available for surveillance programs are scarce.

Keywords

emerging infectious diseases surveillance wild birds distribution models AIV boosted regression trees 

Copyright information

© International Association for Ecology and Health 2010

Authors and Affiliations

  • Julien Cappelle
    • 1
  • Olivier Girard
    • 2
  • Bouba Fofana
    • 3
    • 4
  • Nicolas Gaidet
    • 1
  • Marius Gilbert
    • 5
    • 6
  1. 1.CIRAD ESUR Animal et Gestion intégrée des risques (AGIR)Montpellier Cedex 5France
  2. 2.ONCFS, Réserve de Chanteloupl’Ile d’OlonneFrance
  3. 3.Direction Nationale des Eaux et Forêts du MaliBamakoMali
  4. 4.Wetlands InternationalMopti-SevareMali
  5. 5.Biological Control and Spatial EcologyUniversité Libre de BruxellesBrusselsBelgium
  6. 6.Fonds National de la Recherche ScientifiquesBrusselsBelgium

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