West Nile virus infection in horses, Indian ocean

E. Cardinale (1) , C. Bernard (1) , S. Lecollinet (2) , V M Rakotoharinome (3) , J. Ravaomanana (4) , M. Roger (1) , M.M. Olive (1) , D. Meenowa (5) , M.R. Jaumally (5) , J. Melanie (6) , Jean-Michel Heraud (7) , Stéphan Zientara (2) , C. Cetre-Sossah (1)

1 UMR ASTRE - Animal, Santé, Territoires, Risques et Ecosystèmes
2 VIRO - Virologie UMR1161
3 Direction des Services Vétérinaires
4 FOFIFA - Centre National de Recherche Appliquée au Développement Rural
5 Ministère des Agro-Industries
6 Ministère de l’Agriculture et des Ressources Marines
7 IPM - Unité de Virologie [Antananarivo, Madagascar]

The circulation of West Nile virus (WNV) in horses was investigated in the Southwest Indian ocean. In 2010, blood samples were collected from a total of 303 horses originating from Madagascar, Mauritius, Reunion and the Seychelles and tested for WNV-specific antibodies. An overall seroprevalence of 27.39% was detected in the Indian Ocean with the highest WNV antibody prevalence of 46.22% (95% CI: [37.4–55.2%]) in Madagascar. The age and origin of the horses were found to be associated with the WNV infection risk. This paper presents the first seroprevalence study investigating WN fever in horses in the Southwest Indian Ocean area and indicates a potential risk of infection for humans and animals. In order to gain a better understanding of WN transmission cycles, WNV surveillance needs to be implemented in each of the countries.

Keywords: Antibody prevalence; Indian ocean; West Nile virus; Horses

Domains: Virology; Molecular biology; Emerging diseases; Infectious diseases; Santé publique et épidémiologie

E. Cardinale, C. Bernard, S. Lecollinet, V M Rakotoharinome, J. Ravaomanana, et al.. West Nile virus infection in horses, Indian ocean. Comparative Immunology, Microbiology and Infectious Diseases, 2017, 53, pp.45 - 49. ⟨10.1016/j.cimid.2017.06.006⟩. ⟨pasteur-01675153⟩