Open Access Research

Characterizing the interface between wild ducks and poultry to evaluate the potential of transmission of avian pathogens

Julien Cappelle1*, Nicolas Gaidet1, Samuel A Iverson2, John Y Takekawa2, Scott H Newman3, Bouba Fofana45 and Marius Gilbert67

Author Affiliations

1 CIRAD ES, UR Animal et Gestion intégrée des risques, Montpellier, France

2 USGS Western Ecological Research Center, Vallejo, CA, USA

3 Food and Agriculture Organisation, EMPRES Wildlife Unit, Infectious Disease Group Animal Health Service, Animal Production and Health Division, Rome, Italy

4 Wetlands International, PO Box 471, 6700 AL, Wageningen, The Netherlands

5 Direction Nationale des Eaux et Forêts du Mali, BP 275 Bamako, Mali

6 Biological Control and Spatial Ecology, Université Libre de Bruxelles, av FD Roosevelt, 50, B-1050 Brussels, Belgium

7 Fonds National de la Recherche Scientifiques, rue d'Egmont 5, B-1000 Brussels, Belgium

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International Journal of Health Geographics 2011, 10:60  doi:10.1186/1476-072X-10-60

Published: 15 November 2011

Abstract

Background

Characterizing the interface between wild and domestic animal populations is increasingly recognized as essential in the context of emerging infectious diseases (EIDs) that are transmitted by wildlife. More specifically, the spatial and temporal distribution of contact rates between wild and domestic hosts is a key parameter for modeling EIDs transmission dynamics. We integrated satellite telemetry, remote sensing and ground-based surveys to evaluate the spatio-temporal dynamics of indirect contacts between wild and domestic birds to estimate the risk that avian pathogens such as avian influenza and Newcastle viruses will be transmitted between wildlife to poultry. We monitored comb ducks (Sarkidiornis melanotos melanotos) with satellite transmitters for seven months in an extensive Afro-tropical wetland (the Inner Niger Delta) in Mali and characterise the spatial distribution of backyard poultry in villages. We modelled the spatial distribution of wild ducks using 250-meter spatial resolution and 8-days temporal resolution remotely-sensed environmental indicators based on a Maxent niche modelling method.

Results

Our results show a strong seasonal variation in potential contact rate between wild ducks and poultry. We found that the exposure of poultry to wild birds was greatest at the end of the dry season and the beginning of the rainy season, when comb ducks disperse from natural water bodies to irrigated areas near villages.

Conclusions

Our study provides at a local scale a quantitative evidence of the seasonal variability of contact rate between wild and domestic bird populations. It illustrates a GIS-based methodology for estimating epidemiological contact rates at the wildlife and livestock interface integrating high-resolution satellite telemetry and remote sensing data.

Keywords:
Distribution modelling; Satellite Telemetry; Contact rate; Remote sensing; MODIS; GPS; Maxent