François Charrier

Assessment of Domestic Pigs, Wild Boars and Feral Hybrid Pigs as Reservoirs of Hepatitis E Virus in Corsica, France

In Corsica, extensive pig breeding systems allow frequent interactions between wild boars and domestic pigs, which are suspected to act as reservoirs of several zoonotic diseases including hepatitis E virus (HEV). In this context, 370 sera and 166 liver samples were collected from phenotypically characterized as pure or hybrid wild boars, between 2009 and 2012. In addition, serum and liver from 208 domestic pigs belonging to 30 farms were collected at the abattoir during the end of 2013. Anti-HEV antibodies were detected in 26% (21%–31.6%) of the pure wild boar, 43.5% (31%–56.7%) of hybrid wild boar and 88% (82.6%–91.9%) of the domestic pig sera. In addition, HEV RNA was detected in five wild boars, three hybrid wild boars and two domestic pig livers tested. Our findings provide evidence that both domestic pig and wild boar (pure and hybrid) act as reservoirs of HEV in Corsica, representing an important zoonotic risk for Corsican hunters and farmers but also for the large population of consumers of raw pig liver specialties produced in Corsica. In addition, hybrid wild boars seem to play an important ecological role in the dissemination of HEV between domestic pig and wild boar populations, unnoticed to date, that deserves further investigation.

Applying participatory approaches in the evaluation of surveillance systems: A pilot study on African swine fever surveillance in Corsica

The implementation of regular and relevant evaluations of surveillance systems is critical in improving their effectiveness and their relevance whilst limiting their cost. The complex nature of these systems and the variable contexts in which they are implemented call for the development of flexible evaluation tools. Within this scope, participatory tools have been developed and implemented for the African swine fever (ASF) surveillance system in Corsica (France). The objectives of this pilot study were, firstly, to assess the applicability of participatory approaches within a developed environment involving various stakeholders and, secondly, to define and test methods developed to assess evaluation attributes. Two evaluation attributes were targeted: the acceptability of the surveillance system and its the non-monetary benefits. Individual semi-structured interviews and focus groups were implemented with representatives from every level of the system. Diagramming and scoring tools were used to assess the different elements that compose the definition of acceptability. A contingent valuation method, associated with proportional piling, was used to assess the non-monetary benefits, i.e., the value of sanitary information. Sixteen stakeholders were involved in the process, through 3 focus groups and 8 individual semi-structured interviews. Stakeholders were selected according to their role in the system and to their availability. Results highlighted a moderate acceptability of the system for farmers and hunters and a high acceptability for other representatives (e.g., private veterinarians, local laboratories). Out of the 5 farmers involved in assessing the non-monetary benefits, 3 were interested in sanitary information on ASF. The data collected via participatory approaches enable relevant recommendations to be made, based on the Corsican context, to improve the current surveillance system.

Possible Foodborne Transmission of Hepatitis E Virus from Domestic Pigs and Wild Boars from Corsica.

Author affiliations: ANSES (French Agency for Food, Environmental and Occupational Health and Safety), Maisons-Alfort, France (N. Pavio); INRA (National Institute for Agricultural Research), Maisons-Alfort (N. Pavio); University Paris 12, National Veterinary School, Maisons-Alfort (N. Pavio); INRA, Corte, France (M. Laval, O. Maestrini, F. Casabianca, F. Charrier); CIRAD (Agricultural Research for Development), Montpellier, France (F. Jori); Botswana University of Agriculture and Natural Resources, Gaborone, Botswana (F. Jori)

Questionnaire-Based Assessment of Wild Boar/Domestic Pig Interactions and Implications for Disease Risk Management in Corsica

Wild boars and domestic pigs belong to the same species (Sus scrofa). When sympatric populations of wild boars, feral pigs, and domestic pigs share the same environment, interactions between domestic and wild suids (IDWS) are suspected to facilitate the spread and maintenance of several pig pathogens which can impact on public health and pig production. However, information on the nature and factors facilitating those IDWS are rarely described in the literature. In order to understand the occurrence, nature, and the factors facilitating IDWS, a total of 85 semi-structured interviews were implemented face to face among 25 strict farmers, 20 strict hunters, and 40 hunting farmers in the main traditional pig-farming regions of Corsica, where IDWS are suspected to be common and widespread. Different forms of IDWS were described: those linked with sexual attraction of wild boars by domestic sows (including sexual interactions and fights between wild and domestic boars) were most frequently reported (by 61 and 44% of the respondents, respectively) in the autumn months and early winter. Foraging around common food or water was equally frequent (reported by 60% of the respondents) but spread all along the year except in winter. Spatially, IDWS were more frequent in higher altitude pastures were pig herds remain unattended during summer and autumn months with limited human presence. Abandonment of carcasses and carcass offal in the forest were equally frequent and efficient form of IDWS reported by 70% of the respondents. Certain traditional practices already implemented by hunters and farmers had the potential to mitigate IDWS in the local context. This study provided quantitative evidence of the nature of different IDWS in the context of extensive commercial outdoor pig farming in Corsica and identified their spatial and temporal trends. The identification of those trends is useful to target suitable times and locations to develop further ecological investigations of IDWS at a finer scale in order to better understand diseases transmission patterns between populations and promote adapted management strategies.

Aujeszky's disease and hepatitis E viruses transmission between domestic pigs and wild boars in Corsica: Evaluating the importance of wild/domestic interactions and the efficacy of management measures

Wildlife species as reservoirs of infectious pathogens represent a serious constraint in the implementation of disease management strategies. In the Mediterranean island of Corsica, the dynamics of hepatitis E virus (HEV) and Aujeszky’s disease virus (ADV) are suspected to be influenced by interactions between wild and domestic pigs. To improve our understanding of these influences, we first compared the seroprevalences of both viruses in domestic pig populations from different locations with contrasted levels of wild–domestic interactions, ADV vaccination, biosafety, and farm husbandry. Second, we performed an analysis at a more restricted geographical scale, to assess the matching of ADV or HEV prevalence between sympatric wild boar and outdoor pig farms most exposed to interactions with wildlife. Logistic models were adjusted to the observed data. A high seroprevalence of HEV (>80%) and ADV (40%) in pigs, with no significant difference according to the region, confirms that both pathogens are enzootic in Corsica. Vaccination against ADV had a strong protective effect, even when performed voluntarily by farmers. Farm biosafety had an additional effect on pigs’ exposure, suggesting that contact between wild boars and pigs were involved in disease transmission. A strong correlation in HEV seroprevalence was observed between pigs and wild boars that were in close contact, and significantly lower seroprevalence was observed in pigs when they had little contact with wild boars due to spatial segregation. These results suggest a regular HEV circulation between sympatric wild boar and domestic pigs. The high HEV seroprevalence observed in domestic pigs (>80%) suggests a spillover of the virus from domestic to wild populations through environmental contamination, but this hypothesis has to be confirmed. Conversely, even though avoiding sows’ release on pasture during estrus showed some protecting effect in the free ranging pig farms regarding ADV, ADV seroprevalence was not dependent on the swine populations (wild or domestic) or on the wild–domestic spatial overlap, suggesting two quasi-separate enzootic cycles. This information will prove useful for designing more efficient disease management strategies in Corsica and similar contexts.

Socio-technical lock-in hinders crop diversification in France

Crop diversification is considered as a major lever to increase the sustainability of arable farming systems, allowing reduced inputs (irrigation water, pesticides, fertilizers), increasing the heterogeneity of habitat mosaics, or reducing yield gap associated with too frequent returns of the same species. To free up paths of collective action, this article highlights obstacles to crop diversification, existing at various levels of the value chains. We used a threefold approach: (i) a cross-cutting analysis of impediments to the development of 11 diversifying crops (5 species of grain legumes, alfalfa, flax, hemp, linseed, mustard, sorghum), based on published documents and on 30 interviews of stakeholders in French value chains; (ii) a detailed study (55 semi-structured surveys, including 39 farmers) of three value chains: pea and linseed for animal feed, hemp for insulation and biomaterials; and (iii) a bibliometric analysis of the technical journals and websites (180 articles) to characterize the nature of information diffused to farmers. We highlight that the development of minor crops is hindered by a socio-technical lock-in in favor of the dominant species (wheat, rapeseed, maize, etc.). We show for the first time that this lock-in is characterized by strongly interconnected impediments, occurring at every link of the value chains, such as lack of availability of improved varieties and methods of plant protection, scarcity of quantified references on crop successions, complexity of the knowledge to be acquired by farmers, logistical constraints to harvest collection, and difficulties of coordination within the emerging value chains. On the basis of this lock-in analysis, that could concern other European countries, the article proposes levers aimed at encouraging actors to incorporate a greater diversity of crops into their productive systems: adaptation of standards and labelling, better coordination between stakeholders to fairly share added value within value chains, and combination of genetic, agronomic, technological, and organizational innovations.