title: African swine fever virus transmission cycles in Central Europe: Evaluation of wild boar-soft tick contacts through detection of antibodies against Ornithodoros erraticus saliva antigen.
abstract: BACKGROUND
  African swine fever (ASF) is one of the most complex viral diseases affecting both domestic and wild pigs. It is caused by ASF virus (ASFV), the only DNA virus which can be efficiently transmitted by an arthropod vector, soft ticks of the genus Ornithodoros. These ticks can be part of ASFV-transmission cycles, and in Europe, O. erraticus was shown to be responsible for long-term maintenance of ASFV in Spain and Portugal. In 2014, the disease has been reintroduced into the European Union, affecting domestic pigs and, importantly, also the Eurasian wild boar population. In a first attempt to assess the risk of a tick-wild boar transmission cycle in Central Europe that would further complicate eradication of the disease, over 700 pre-existing serum samples from wild boar hunted in four representative German Federal States were investigated for the presence of antibodies directed against salivary antigen of Ornithodoros erraticus ticks using an indirect ELISA format.
  
  
  RESULTS
  Out of these samples, 16 reacted with moderate to high optical densities that could be indicative of tick bites in sampled wild boar. However, these samples did not show a spatial clustering (they were collected from distant geographical regions) and were of bad quality (hemolysis/impurities). Furthermore, all positive samples came from areas with suboptimal climate for soft ticks. For this reason, false positive reactions are likely.
  
  
  CONCLUSIONS
  In conclusion, the study did not provide stringent evidence for soft tick-wild boar contact in the investigated German Federal States and thus, a relevant involvement in the epidemiology of ASF in German wild boar is unlikely. This fact would facilitate the eradication of ASF in the area, although other complex relations (wild boar biology and interactions with domestic pigs) need to be considered.
authors.affiliation: Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493, Greifswald-Insel Riems, Germany. jana.pietschmann@fli.bund.de.
authors.forename: Jana
authors.initials: J
authors.lastname: Pietschmann
authors.affiliation: VISAVET Center and Animal Health Department, Veterinary School, Universidad Complutense de Madrid, Avenida Puerta de Hierro s/n, 28040, Madrid, Spain. lina@sanidadanimal.info.
authors.forename: Lina
authors.initials: L
authors.lastname: Mur
authors.affiliation: Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493, Greifswald-Insel Riems, Germany. sandra.blome@fli.bund.de.
authors.forename: Sandra
authors.initials: S
authors.lastname: Blome
authors.affiliation: Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493, Greifswald-Insel Riems, Germany. martin.beer@fli.bund.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Beer
authors.affiliation: Parasitología, IRNASA (CSIC), Cordel de Merinas, 40-52, 37008, Salamanca, Spain. ricardo.perez@irnasa.csic.es.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pérez-Sánchez
authors.affiliation: Parasitología, IRNASA (CSIC), Cordel de Merinas, 40-52, 37008, Salamanca, Spain. ana.oleaga@irnasa.csic.es.
authors.forename: Ana
authors.initials: A
authors.lastname: Oleaga
authors.affiliation: VISAVET Center and Animal Health Department, Veterinary School, Universidad Complutense de Madrid, Avenida Puerta de Hierro s/n, 28040, Madrid, Spain. jmvizcaino@ucm.es.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Sánchez-Vizcaíno
mesh_terms: D000357:African Swine Fever / Q000276:immunology / Q000635:transmission*; D000358:African Swine Fever Virus; D000818:Animals; D000906:Antibodies / Q000032:analysis*; D005858:Germany; D007299:Insect Bites and Stings / Q000276:immunology; D026861:Ornithodoros / Q000276:immunology*; D012463:Saliva / Q000276:immunology; D034421:Sus scrofa / Q000276:immunology*; D013552:Swine
chemical_list: D000906:Antibodies