Threat to the French Swine Industry of African Swine Fever: Surveillance, Spread, and Control Perspectives

African swine fever (ASF) has one of the highest case-fatality rates among pig diseases. Europe was considered ASF-free for about two decades until 2007, when the virus was introduced into Georgia. Since then, it has been identified throughout Eastern Europe, and reached Belgium in late 2018, increa...

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Main Authors: Mathieu Andraud, Tariq Halasa, Anette Boklund, Nicolas Rose
Format: Article
Language:English
Published: Frontiers Media S.A. 2019-07-01
Series:Frontiers in Veterinary Science
Subjects:
Online Access:https://www.frontiersin.org/article/10.3389/fvets.2019.00248/full
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author Mathieu Andraud
Mathieu Andraud
Tariq Halasa
Anette Boklund
Nicolas Rose
Nicolas Rose
author_facet Mathieu Andraud
Mathieu Andraud
Tariq Halasa
Anette Boklund
Nicolas Rose
Nicolas Rose
author_sort Mathieu Andraud
collection DOAJ
description African swine fever (ASF) has one of the highest case-fatality rates among pig diseases. Europe was considered ASF-free for about two decades until 2007, when the virus was introduced into Georgia. Since then, it has been identified throughout Eastern Europe, and reached Belgium in late 2018, increasing the risk of ASF being introduced into neighboring countries—namely Germany, Luxembourg, the Netherlands, and France. French authorities have therefore reinforced surveillance measures to improve the probability of detecting ASF rapidly if it emerges in France. Predictive modeling may help to anticipate the extent of virus spread and evaluate the efficiency of these surveillance measures. A previously published and well-documented model that simulates ASF virus spread was therefore tailored to realistically represent the French situation in terms of the geographic distribution of swine production sites and the commercial trade between them on the one hand, and the implementation of surveillance protocols on the other. The outcomes confirmed the moderate spread of ASF through the swine trade network, a situation that had been previously highlighted for the case of Denmark. However, the diversity of the French pig production landscape has revealed a huge potential for the geographic dispersal of the virus, especially should the index case occur in a low-density area, with a median source-to-case distance reaching 300 km. Free-range herds, which are more likely to have interactions with wild boars, were also identified as potential entrance gate for the virus. Transmissions from conventional herds were quasi-exclusively due to swine movement on the commercial network, representing 99% of transmission events. In contrast, 81% of transmission events occurred in the neighborhood of the index herd when the virus was introduced in free-range herds. The current surveillance measures were found relatively efficient for detecting the virus in large herds, leading to detection rates of 94%. However, infections on smaller production sites—which often have free-range herds—were more difficult to detect and would require screening protocols specifically targeting these smaller herds.
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spelling doaj.art-6bc86a60d5f14196938eeb91749a6d732022-12-22T00:01:58ZengFrontiers Media S.A.Frontiers in Veterinary Science2297-17692019-07-01610.3389/fvets.2019.00248469963Threat to the French Swine Industry of African Swine Fever: Surveillance, Spread, and Control PerspectivesMathieu Andraud0Mathieu Andraud1Tariq Halasa2Anette Boklund3Nicolas Rose4Nicolas Rose5Ploufragan-Plouzané Laboratory, Epidemiology Health and Welfare Department, ANSES, Ploufragan, FranceBretagne-Loire University, Rennes, FranceDepartment of Veterinary and Animal Science, University of Copenhagen, Copenhagen, DenmarkDepartment of Veterinary and Animal Science, University of Copenhagen, Copenhagen, DenmarkPloufragan-Plouzané Laboratory, Epidemiology Health and Welfare Department, ANSES, Ploufragan, FranceBretagne-Loire University, Rennes, FranceAfrican swine fever (ASF) has one of the highest case-fatality rates among pig diseases. Europe was considered ASF-free for about two decades until 2007, when the virus was introduced into Georgia. Since then, it has been identified throughout Eastern Europe, and reached Belgium in late 2018, increasing the risk of ASF being introduced into neighboring countries—namely Germany, Luxembourg, the Netherlands, and France. French authorities have therefore reinforced surveillance measures to improve the probability of detecting ASF rapidly if it emerges in France. Predictive modeling may help to anticipate the extent of virus spread and evaluate the efficiency of these surveillance measures. A previously published and well-documented model that simulates ASF virus spread was therefore tailored to realistically represent the French situation in terms of the geographic distribution of swine production sites and the commercial trade between them on the one hand, and the implementation of surveillance protocols on the other. The outcomes confirmed the moderate spread of ASF through the swine trade network, a situation that had been previously highlighted for the case of Denmark. However, the diversity of the French pig production landscape has revealed a huge potential for the geographic dispersal of the virus, especially should the index case occur in a low-density area, with a median source-to-case distance reaching 300 km. Free-range herds, which are more likely to have interactions with wild boars, were also identified as potential entrance gate for the virus. Transmissions from conventional herds were quasi-exclusively due to swine movement on the commercial network, representing 99% of transmission events. In contrast, 81% of transmission events occurred in the neighborhood of the index herd when the virus was introduced in free-range herds. The current surveillance measures were found relatively efficient for detecting the virus in large herds, leading to detection rates of 94%. However, infections on smaller production sites—which often have free-range herds—were more difficult to detect and would require screening protocols specifically targeting these smaller herds.https://www.frontiersin.org/article/10.3389/fvets.2019.00248/fullpignotifiable diseasemodelingepidemiologyASF
spellingShingle Mathieu Andraud
Mathieu Andraud
Tariq Halasa
Anette Boklund
Nicolas Rose
Nicolas Rose
Threat to the French Swine Industry of African Swine Fever: Surveillance, Spread, and Control Perspectives
Frontiers in Veterinary Science
pig
notifiable disease
modeling
epidemiology
ASF
title Threat to the French Swine Industry of African Swine Fever: Surveillance, Spread, and Control Perspectives
title_full Threat to the French Swine Industry of African Swine Fever: Surveillance, Spread, and Control Perspectives
title_fullStr Threat to the French Swine Industry of African Swine Fever: Surveillance, Spread, and Control Perspectives
title_full_unstemmed Threat to the French Swine Industry of African Swine Fever: Surveillance, Spread, and Control Perspectives
title_short Threat to the French Swine Industry of African Swine Fever: Surveillance, Spread, and Control Perspectives
title_sort threat to the french swine industry of african swine fever surveillance spread and control perspectives
topic pig
notifiable disease
modeling
epidemiology
ASF
url https://www.frontiersin.org/article/10.3389/fvets.2019.00248/full
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