West Nile virus outbreak in horses, southern France, 2000: results of a serosurvey.
During late summer and autumn 2000, a West Nile fever outbreak in southern France resulted in 76 equine clinical cases; 21 horses died. We report the results of a large serosurvey of all equines within a 10-km radius of laboratory-confirmed cases. Blood samples were obtained from 5,107 equines, distributed in groups of 1 to 91 animals. West Nile virus immunoglobulin (Ig) G antibodies were found in 8.5% of animals (n=432). Forty-two percent of the IgG-positive animals were also IgM positive. Horses living in small groups were more affected than those in large groups. The results suggest that West Nile virus is not endemic in the affected area, the Camargue; rather, sporadic outbreaks are separated by long silent periods.
Agence Français de Sécurité Sanitaire des Aliments, Maisons-Alfort, France. bdurand@afssa.fr
Benoit
B
Durand
Véronique
V
Chevalier
Régis
R
Pouillot
Jacques
J
Labie
Ingrid
I
Marendat
Bernadette
B
Murgue
Hervé
H
Zeller
Stéphan
S
Zientara
D000367:Age Factors; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001717:Birds; D002353:Carrier State / Q000662:veterinary / Q000821:virology; D021821:Communicable Diseases, Emerging / Q000097:blood / Q000453:epidemiology / Q000662:veterinary; D004196:Disease Outbreaks / Q000662:veterinary*; D005260:Female; D005602:France; D006306:Health Surveys; D006734:Horse Diseases / Q000097:blood / Q000453:epidemiology* / Q000821:virology*; D006736:Horses; D007074:Immunoglobulin G / Q000097:blood; D016015:Logistic Models; D008297:Male; D013997:Time Factors; D014901:West Nile Fever / Q000097:blood / Q000453:epidemiology* / Q000662:veterinary*; D014902:West Nile virus / Q000302:isolation & purification*
D000914:Antibodies, Viral; D007074:Immunoglobulin G