Serological status for BTV-8 in French cattle prior to the 2015 re-emergence
2018
Courtejoie, N. | Durand, B. | Bréard, E. | Sailleau, C. | Vitour, D. | Zientara, Stéphan | Gorlier, A. | Baurier, F. | Gourmelen, C. | Benoit, Fabienne | Achour, Hamid | Milard, C. | Poliak, S. | Pagneux, C. | Viarouge, C. | Zanella, G. | Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES) | Virologie UMR1161 (VIRO) ; École nationale vétérinaire d'Alfort (ENVA)-Laboratoire de santé animale, sites de Maisons-Alfort et de Normandie ; Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES)-Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Association française des Directeurs et cadres de Laboratoires Vétérinaires publics d'Analyses (ADILVA) | Laboratoire départemental d'analyses 18 | Laboratoire Départemental d'Analyses 37 (LDA37) | LABÉO, Pôle d’analyses et de recherche de Normandie (LABÉO) | Laboratoire départemental d'analyses 69 | INOVALYS | Eurofins Laboratoire Cœur de France | ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010)
International audience
显示更多 [+] 显示较少 [-]英语. Undetected in Europe since 2010, bluetongue virus serotype 8 (BTV-8) re-emerged in August 2015 in Central France. To gain insight into the re-emergence on the French territory, we estimated the seroprevalence in cattle before the detection of BTV-8 in 2015, in areas differentially affected by the current outbreak. A retrospective survey based on the analysis of stored sera was thus conducted in the winter preceding the re-emergence in seven French departments including the one where the virus was first detected. A total of 10,066 sera were retrieved from animals sampled in 444 different herds in winter 2014/15. Between-herd seroprevalence revealed the presence of seropositive animals in almost all herds sampled (97.4%). The animal-level seroprevalence averaged at 44%, with a strong age pattern reflecting the cumulative exposure to both natural infection and to vaccination. A multivariable analysis allowed separating the respective effects of both exposures. A higher proportion of seropositivity risk was attributed to vaccination (67.4%) than to exposure to natural infection (24.2%). The evolution of seroprevalence induced by the two main risk factors in 74 mainland departments was reconstructed between the vaccination ban (2013) and the re-emergence (2015). We showed a striking decrease in seroprevalence with time after the vaccination ban, due to population renewal, which could have facilitated virus transmission leading to the current outbreak situation.
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