In response to the threat of African swine fever entry in EU, posed by its spreading in Eastern Europe, the ASFORCE project aims at providing veterinarians, pig farmers, hunters and policy makers with practical answers and prevention tools against the disease.

Under coordination and management activities planned under Theme 1 (Coordination and management), the scientific and technological work plan of ASFORCE is divided in four Themes, each aiming at particular objectives to reinforce the overall goals of the project.

During the first period of the project development (01/10/2012 – 31/03/2014), scientific and technological work has progressed according to the work plan within the different Themes:

 

THEME 2 - Prevention, control and eradication models for ASF

Very detailed data was compiled on pig production in dense livestock areas and in areas with backyard farming. Pig trade movements were explored for some EU countries, revealing marked differences in the trade patterns depending on the type of premises and management systems in place. Standardized genotyping of ASFV in Sardinia and Russia revealed a single introduction in both places. Sequencing of an intergenic region indicates the Lithuanian and Polish ASFV is identical to recent isolates but differ from the first isolated in Georgia (2007). The full genome sequences of three ASFV from Russian Federation (RF) are under process.

The existing data on surveillance and control plans for ASF was compiled and reviewed for countries in different scenarios: free, endemic and countries where ASF was detected in wild boar. Data on programs’ costs was compiled for Sardinia and five regions of RF.

Data on ASF transmission and survival data were evaluated in transmission experiments; the importance of wild boar-to-farm transmission was also assessed in the Tver region (RF). This information will be included in a dynamic spread model to evaluate the spread of ASF and the cost-efficacy of different control measures. The results of this model, together with the outputs of other WPs will be used to define guidelines for better preventing and controlling ASF.

 

THEME 3 - Pig-wild boar-argasidae interactions relevant for ASF epidemiology

Efforts on tick sampling have been developed: a practical training course, a field collection in Krasnodar & Sardinia (negative results) and a predictive tick map. Now, the tick sample protocol is ready. The tick-pig/wild boar interactions were assayed in 3000 serum samples showing strong positive results in Russian Federation. The vector competence and influence of salivary glands in ASFV studies were done in O. moubata and porcinus. Due to the problems encountered to find O.asperus, O.erraticus will be employed. Regarding wild boar and domestic pig interactions, pilot questionnaires have been developed and tested in 6 countries; GPS studies are being conducted in four locations; biomarkers showed promising results (E. coli) but applicability needs further assessment.

Mapping activities comprises a pig holding map in Eurasia and different WB models based on: habitat suitability and hunting/observational data (three countries); environmental variables & presence records (MaxEnt) (specific regions); hunting data (whole Europe). To improve them, a potential abundance map is being developed. The reproduction rate of ASF in WB has been estimated as 133.1 Km.

Further characterization of European wild boar infection by the Caucasian ASFV isolate and by a recent Sardinian isolate under lab conditions, confirmed the high virulence of both virus.

 

THEME 4 - Development of protection tools against ASF

Candidate vaccines and improved diagnostic tests are being developed.  Genes involved in suppressing innate immune responses, including type I interferon, have been selected for deletion from already attenuated or from virulent ASFV strains. Deletion of 9 genes from a virulent isolate from West Africa resulted in attenuation and induction of a protective response against lethal challenge. Transmission of an attenuated strain 9 weeks after inoculation was demonstrated.

Production of defective infectious single cycle (DISC) virus is an alternative vaccine approach. This requires a helper cell line expressing an essential gene to produce infectious progeny. Six putative essential genes have been evaluated for this role and construction of helper cell liness in progress.

T cell epitopes have been predicted in silico. 188 protein sequences were screened for the presence of 9mer peptides predicted to bind to 45 different SLA-I haplotypes. A prioritised list of ASFV proteins to be tested in pigs for their capacity to induce a protective response was generated. Cloning of 8 of these genes in vaccine vectors including BacMAM, parapox and parvovirus like particles is in progress.

New diagnostic tools developed include an ELISA to detect antibodies against ASFV at significantly earlier times post-infection than current ELISA tests. A lateral flow device for penside detection of ASFV antigen has been developed and tested.

 

THEME 5 - Training and knowledge transfer

A survey was developed to investigate the attitude of pig farmers and hunters towards reporting suspected cases of ASF. A leaflet was created addressing the key ASF topics. It was translated into eight languages, available at the project website and further disseminated by different means.

Three workshops on disease preparedness were organised (Madrid, Spain; Pokrov, Russian Federation and Sofia, Bulgaria). In total, more than 100 veterinarians were trained.

An interactive online training course on ASF, available online through this website contains relevant information on topics included in three modules.

 

The reported results indicated an adequate progress of the project in agreement with the work plan.