Landscape attributes driving avian influenza virus circulation in the Lake Alaotra region of Madagascar

Guerrini Laure, Paul Mathilde, Leger Lucas, Harentsoaniaina Rasamoelina Andriamanivo, Maminiaina Olivier Fridolin, Jourdan Marion, Molia Sophie, Rakotondravao René, Chevalier Véronique. 2014. Landscape attributes driving avian influenza virus circulation in the Lake Alaotra region of Madagascar. Geospatial Health, 8 (2) : pp. 445-453.

Journal article ; Article de revue à facteur d'impact
Published version - Anglais
Use under authorization by the author or CIRAD.

Télécharger (1MB) | Preview


Abstract : While the spatial pattern of the highly pathogenic avian influenza H5N1 virus has been studied throughout Southeast Asia, little is known on the spatial risk factors for avian influenza in Africa. In the present paper, we combined serological data from poultry and remotely sensed environmental factors in the Lake Alaotra region of Madagascar to explore for any association between avian influenza and landscape variables. Serological data from cross-sectional surveys carried out on poultry in 2008 and 2009 were examined together with a Landsat 7 satellite image analysed using supervised classification. The dominant landscape features in a 1-km buffer around farmhouses and distance to the closest water body were extracted. A total of 1,038 individual bird blood samples emanating from 241 flocks were analysed, and the association between avian influenza seroprevalence and these landcape variables was quantified using logistic regression models. No evidence of the presence of H5 or H7 avian influenza subtypes was found, suggesting that only low pathogenic avian influenza (LPAI) circulated. Three predominant land cover classes were identified around the poultry farms: grassland savannah, rice paddy fields and wetlands. A significant negative relationship was found between LPAI seroprevalence and distance to the closest body of water. We also found that LPAI seroprevalence was higher in farms characterised by predominant wetlands or rice landscapes than in those surrounded by dry savannah. Results from this study suggest that if highly pathogenic avian influenza H5N1 virus were introduced in Madagascar, the environmental conditions that prevail in Lake Alaotra region may allow the virus to spread and persist. (Résumé d'auteur)

Mots-clés Agrovoc : Influenzavirus aviaire, Épidémiologie, Sérologie, Paysage, Facteur de risque, Facteur du milieu, Couverture végétale, Savane, Zone humide, Rizière, Enquête pathologique, Distribution géographique, Télédétection, Landsat

Mots-clés géographiques Agrovoc : Madagascar

Mots-clés géographiques complémentaires : Lac Alaotra

Classification Agris : L73 - Animal diseases
U30 - Research methods
B10 - Geography

Champ stratégique Cirad : Axe 4 (2014-2018) - Santé des animaux et des plantes

Auteurs et affiliations

  • Guerrini Laure, CIRAD-ES-UPR AGIRs (ZWE)
  • Paul Mathilde, ENVT (FRA)
  • Leger Lucas
  • Harentsoaniaina Rasamoelina Andriamanivo, CENDRADERU (MDG)
  • Maminiaina Olivier Fridolin, CENDRADERU (MDG)
  • Jourdan Marion, AVSF (FRA)
  • Molia Sophie, CIRAD-ES-UPR AGIRs (FRA)
  • Rakotondravao René, CENDRADERU (MDG)
  • Chevalier Véronique, CIRAD-ES-UPR AGIRs (FRA)

Source : Cirad - Agritrop (

View Item (staff only) View Item (staff only)

[ Page générée et mise en cache le 2021-02-26 ]