Importance of wetlands management for West Nile Virus circulation risk, Camargue, Southern France

Sophie Pradier (1) , Alain Sandoz (2, 3) , Mathilde C. Paul (1) , Gaëtan Lefebvre (2) , Annelise Tran (4, 5) , Josiane Maingault (6) , Sylvie Lecollinet (6) , Agnès Leblond (7)

1 IHAP - Interactions hôtes-agents pathogènes [Toulouse]
2 Centre de recherche de la Tour du Valat
3 AMU SCI - Aix-Marseille Université - Faculté des Sciences
4 UPR AGIRs - Animal et gestion intégrée des risques
5 UMR TETIS - Territoires, Environnement, Télédétection et Information Spatiale
6 VIRO - Virologie UMR1161
7 Pôle Equin

To assess environmental and horse-level risk factors associated with West Nile Virus (WNV) circulation in Camargue, Southern France, a serosurvey was conducted on non-vaccinated horses (n = 1159 from 134 stables) in 2007 and 2008. Fifteen Landsat images were examined to quantify areas with open water and flooded vegetation around sampled horses. Mean percentages of areas of open water and flooded vegetation, as well as variations in these percentages between 3 periods (November to February = NOT, March to July = END and August to October = EPI), were calculated for buffers of 2 km radius around the stables. Results of the final logistic regression showed that the risk of WNV seropositivity in horses decreased with their date of acquisition and age. Results also demonstrated the significant role of environmental variables. Horse serological status was associated with variations of open water areas between the NOT (November to February) and END (March to July) periods, as well as between END and EPI (August to October). WNV spillover was found more intense in areas where water level decreased strongly from winter to spring and from spring to summer.

Mots clés: France; risk factor; vector-borne; wetlands; spatial analysis

Domaines: Sciences du Vivant [q-bio]

Sophie Pradier, Alain Sandoz, Mathilde C. Paul, Gaëtan Lefebvre, Annelise Tran, et al.. Importance of wetlands management for West Nile Virus circulation risk, Camargue, Southern France. International Journal of Environmental Research and Public Health, 2014, 11 (8), pp.7740-7754. ⟨10.3390/ijerph110807740⟩. ⟨hal-01190092⟩